publicdata/nist-gov
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions
nist-gov/www.nist.gov/blogs/taking-measure/taking-seat-periodic-table
Scott Williams 4063bef310 Initital commit.
2025-03-05 18:59:57 +00:00

1410 lines
110 KiB
Text
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

<!DOCTYPE html>
<html lang="en" dir="ltr" prefix="content: http://purl.org/rss/1.0/modules/content/ dc: http://purl.org/dc/terms/ foaf: http://xmlns.com/foaf/0.1/ og: http://ogp.me/ns# rdfs: http://www.w3.org/2000/01/rdf-schema# schema: http://schema.org/ sioc: http://rdfs.org/sioc/ns# sioct: http://rdfs.org/sioc/types# skos: http://www.w3.org/2004/02/skos/core# xsd: http://www.w3.org/2001/XMLSchema# ">
<head>
<meta charset="utf-8" /><script type="text/javascript">(window.NREUM||(NREUM={})).init={ajax:{deny_list:["bam.nr-data.net"]}};(window.NREUM||(NREUM={})).loader_config={licenseKey:"37b7ccb661",applicationID:"1089704227"};;/*! For license information please see nr-loader-rum-1.283.2.min.js.LICENSE.txt */
(()=>{var e,t,r={122:(e,t,r)=>{"use strict";r.d(t,{a:()=>i});var n=r(944);function i(e,t){try{if(!e||"object"!=typeof e)return(0,n.R)(3);if(!t||"object"!=typeof t)return(0,n.R)(4);const r=Object.create(Object.getPrototypeOf(t),Object.getOwnPropertyDescriptors(t)),o=0===Object.keys(r).length?e:r;for(let a in o)if(void 0!==e[a])try{if(null===e[a]){r[a]=null;continue}Array.isArray(e[a])&&Array.isArray(t[a])?r[a]=Array.from(new Set([...e[a],...t[a]])):"object"==typeof e[a]&&"object"==typeof t[a]?r[a]=i(e[a],t[a]):r[a]=e[a]}catch(e){(0,n.R)(1,e)}return r}catch(e){(0,n.R)(2,e)}}},555:(e,t,r)=>{"use strict";r.d(t,{Vp:()=>c,fn:()=>s,x1:()=>u});var n=r(384),i=r(122);const o={beacon:n.NT.beacon,errorBeacon:n.NT.errorBeacon,licenseKey:void 0,applicationID:void 0,sa:void 0,queueTime:void 0,applicationTime:void 0,ttGuid:void 0,user:void 0,account:void 0,product:void 0,extra:void 0,jsAttributes:{},userAttributes:void 0,atts:void 0,transactionName:void 0,tNamePlain:void 0},a={};function s(e){try{const t=c(e);return!!t.licenseKey&&!!t.errorBeacon&&!!t.applicationID}catch(e){return!1}}function c(e){if(!e)throw new Error("All info objects require an agent identifier!");if(!a[e])throw new Error("Info for ".concat(e," was never set"));return a[e]}function u(e,t){if(!e)throw new Error("All info objects require an agent identifier!");a[e]=(0,i.a)(t,o);const r=(0,n.nY)(e);r&&(r.info=a[e])}},217:(e,t,r)=>{"use strict";r.d(t,{D0:()=>m,gD:()=>v,xN:()=>h});r(860).K7.genericEvents;const n="experimental.marks",i="experimental.measures",o="experimental.resources",a=e=>{if(!e||"string"!=typeof e)return!1;try{document.createDocumentFragment().querySelector(e)}catch{return!1}return!0};var s=r(614),c=r(944),u=r(384),l=r(122);const d="[data-nr-mask]",f=()=>{const e={feature_flags:[],experimental:{marks:!1,measures:!1,resources:!1},mask_selector:"*",block_selector:"[data-nr-block]",mask_input_options:{color:!1,date:!1,"datetime-local":!1,email:!1,month:!1,number:!1,range:!1,search:!1,tel:!1,text:!1,time:!1,url:!1,week:!1,textarea:!1,select:!1,password:!0}};return{ajax:{deny_list:void 0,block_internal:!0,enabled:!0,autoStart:!0},distributed_tracing:{enabled:void 0,exclude_newrelic_header:void 0,cors_use_newrelic_header:void 0,cors_use_tracecontext_headers:void 0,allowed_origins:void 0},get feature_flags(){return e.feature_flags},set feature_flags(t){e.feature_flags=t},generic_events:{enabled:!0,autoStart:!0},harvest:{interval:30},jserrors:{enabled:!0,autoStart:!0},logging:{enabled:!0,autoStart:!0},metrics:{enabled:!0,autoStart:!0},obfuscate:void 0,page_action:{enabled:!0},page_view_event:{enabled:!0,autoStart:!0},page_view_timing:{enabled:!0,autoStart:!0},performance:{get capture_marks(){return e.feature_flags.includes(n)||e.experimental.marks},set capture_marks(t){e.experimental.marks=t},get capture_measures(){return e.feature_flags.includes(i)||e.experimental.measures},set capture_measures(t){e.experimental.measures=t},capture_detail:!0,resources:{get enabled(){return e.feature_flags.includes(o)||e.experimental.resources},set enabled(t){e.experimental.resources=t},asset_types:[],first_party_domains:[],ignore_newrelic:!0}},privacy:{cookies_enabled:!0},proxy:{assets:void 0,beacon:void 0},session:{expiresMs:s.wk,inactiveMs:s.BB},session_replay:{autoStart:!0,enabled:!1,preload:!1,sampling_rate:10,error_sampling_rate:100,collect_fonts:!1,inline_images:!1,fix_stylesheets:!0,mask_all_inputs:!0,get mask_text_selector(){return e.mask_selector},set mask_text_selector(t){a(t)?e.mask_selector="".concat(t,",").concat(d):""===t||null===t?e.mask_selector=d:(0,c.R)(5,t)},get block_class(){return"nr-block"},get ignore_class(){return"nr-ignore"},get mask_text_class(){return"nr-mask"},get block_selector(){return e.block_selector},set block_selector(t){a(t)?e.block_selector+=",".concat(t):""!==t&&(0,c.R)(6,t)},get mask_input_options(){return e.mask_input_options},set mask_input_options(t){t&&"object"==typeof t?e.mask_input_options={...t,password:!0}:(0,c.R)(7,t)}},session_trace:{enabled:!0,autoStart:!0},soft_navigations:{enabled:!0,autoStart:!0},spa:{enabled:!0,autoStart:!0},ssl:void 0,user_actions:{enabled:!0,elementAttributes:["id","className","tagName","type"]}}},g={},p="All configuration objects require an agent identifier!";function m(e){if(!e)throw new Error(p);if(!g[e])throw new Error("Configuration for ".concat(e," was never set"));return g[e]}function h(e,t){if(!e)throw new Error(p);g[e]=(0,l.a)(t,f());const r=(0,u.nY)(e);r&&(r.init=g[e])}function v(e,t){if(!e)throw new Error(p);var r=m(e);if(r){for(var n=t.split("."),i=0;i<n.length-1;i++)if("object"!=typeof(r=r[n[i]]))return;r=r[n[n.length-1]]}return r}},371:(e,t,r)=>{"use strict";r.d(t,{V:()=>f,f:()=>d});var n=r(122),i=r(384),o=r(154),a=r(324);let s=0;const c={buildEnv:a.F3,distMethod:a.Xs,version:a.xv,originTime:o.WN},u={customTransaction:void 0,disabled:!1,isolatedBacklog:!1,loaderType:void 0,maxBytes:3e4,onerror:void 0,ptid:void 0,releaseIds:{},appMetadata:{},session:void 0,denyList:void 0,timeKeeper:void 0,obfuscator:void 0,harvester:void 0},l={};function d(e){if(!e)throw new Error("All runtime objects require an agent identifier!");if(!l[e])throw new Error("Runtime for ".concat(e," was never set"));return l[e]}function f(e,t){if(!e)throw new Error("All runtime objects require an agent identifier!");l[e]={...(0,n.a)(t,u),...c},Object.hasOwnProperty.call(l[e],"harvestCount")||Object.defineProperty(l[e],"harvestCount",{get:()=>++s});const r=(0,i.nY)(e);r&&(r.runtime=l[e])}},324:(e,t,r)=>{"use strict";r.d(t,{F3:()=>i,Xs:()=>o,xv:()=>n});const n="1.283.2",i="PROD",o="CDN"},154:(e,t,r)=>{"use strict";r.d(t,{OF:()=>c,RI:()=>i,WN:()=>l,bv:()=>o,gm:()=>a,mw:()=>s,sb:()=>u});var n=r(863);const i="undefined"!=typeof window&&!!window.document,o="undefined"!=typeof WorkerGlobalScope&&("undefined"!=typeof self&&self instanceof WorkerGlobalScope&&self.navigator instanceof WorkerNavigator||"undefined"!=typeof globalThis&&globalThis instanceof WorkerGlobalScope&&globalThis.navigator instanceof WorkerNavigator),a=i?window:"undefined"!=typeof WorkerGlobalScope&&("undefined"!=typeof self&&self instanceof WorkerGlobalScope&&self||"undefined"!=typeof globalThis&&globalThis instanceof WorkerGlobalScope&&globalThis),s=Boolean("hidden"===a?.document?.visibilityState),c=/iPad|iPhone|iPod/.test(a.navigator?.userAgent),u=c&&"undefined"==typeof SharedWorker,l=((()=>{const e=a.navigator?.userAgent?.match(/Firefox[/\s](\d+\.\d+)/);Array.isArray(e)&&e.length>=2&&e[1]})(),Date.now()-(0,n.t)())},687:(e,t,r)=>{"use strict";r.d(t,{Ak:()=>c,Ze:()=>d,x3:()=>u});var n=r(836),i=r(606),o=r(860),a=r(646);const s={};function c(e,t){const r={staged:!1,priority:o.P3[t]||0};l(e),s[e].get(t)||s[e].set(t,r)}function u(e,t){e&&s[e]&&(s[e].get(t)&&s[e].delete(t),g(e,t,!1),s[e].size&&f(e))}function l(e){if(!e)throw new Error("agentIdentifier required");s[e]||(s[e]=new Map)}function d(e="",t="feature",r=!1){if(l(e),!e||!s[e].get(t)||r)return g(e,t);s[e].get(t).staged=!0,f(e)}function f(e){const t=Array.from(s[e]);t.every((([e,t])=>t.staged))&&(t.sort(((e,t)=>e[1].priority-t[1].priority)),t.forEach((([t])=>{s[e].delete(t),g(e,t)})))}function g(e,t,r=!0){const o=e?n.ee.get(e):n.ee,s=i.i.handlers;if(!o.aborted&&o.backlog&&s){if(r){const e=o.backlog[t],r=s[t];if(r){for(let t=0;e&&t<e.length;++t)p(e[t],r);Object.entries(r).forEach((([e,t])=>{Object.values(t||{}).forEach((t=>{t[0]?.on&&t[0]?.context()instanceof a.y&&t[0].on(e,t[1])}))}))}}o.isolatedBacklog||delete s[t],o.backlog[t]=null,o.emit("drain-"+t,[])}}function p(e,t){var r=e[1];Object.values(t[r]||{}).forEach((t=>{var r=e[0];if(t[0]===r){var n=t[1],i=e[3],o=e[2];n.apply(i,o)}}))}},836:(e,t,r)=>{"use strict";r.d(t,{P:()=>c,ee:()=>u});var n=r(384),i=r(990),o=r(371),a=r(646),s=r(607);const c="nr@context:".concat(s.W),u=function e(t,r){var n={},s={},l={},d=!1;try{d=16===r.length&&(0,o.f)(r).isolatedBacklog}catch(e){}var f={on:p,addEventListener:p,removeEventListener:function(e,t){var r=n[e];if(!r)return;for(var i=0;i<r.length;i++)r[i]===t&&r.splice(i,1)},emit:function(e,r,n,i,o){!1!==o&&(o=!0);if(u.aborted&&!i)return;t&&o&&t.emit(e,r,n);for(var a=g(n),c=m(e),l=c.length,d=0;d<l;d++)c[d].apply(a,r);var p=v()[s[e]];p&&p.push([f,e,r,a]);return a},get:h,listeners:m,context:g,buffer:function(e,t){const r=v();if(t=t||"feature",f.aborted)return;Object.entries(e||{}).forEach((([e,n])=>{s[n]=t,t in r||(r[t]=[])}))},abort:function(){f._aborted=!0,Object.keys(f.backlog).forEach((e=>{delete f.backlog[e]}))},isBuffering:function(e){return!!v()[s[e]]},debugId:r,backlog:d?{}:t&&"object"==typeof t.backlog?t.backlog:{},isolatedBacklog:d};return Object.defineProperty(f,"aborted",{get:()=>{let e=f._aborted||!1;return e||(t&&(e=t.aborted),e)}}),f;function g(e){return e&&e instanceof a.y?e:e?(0,i.I)(e,c,(()=>new a.y(c))):new a.y(c)}function p(e,t){n[e]=m(e).concat(t)}function m(e){return n[e]||[]}function h(t){return l[t]=l[t]||e(f,t)}function v(){return f.backlog}}(void 0,"globalEE"),l=(0,n.Zm)();l.ee||(l.ee=u)},646:(e,t,r)=>{"use strict";r.d(t,{y:()=>n});class n{constructor(e){this.contextId=e}}},908:(e,t,r)=>{"use strict";r.d(t,{d:()=>n,p:()=>i});var n=r(836).ee.get("handle");function i(e,t,r,i,o){o?(o.buffer([e],i),o.emit(e,t,r)):(n.buffer([e],i),n.emit(e,t,r))}},606:(e,t,r)=>{"use strict";r.d(t,{i:()=>o});var n=r(908);o.on=a;var i=o.handlers={};function o(e,t,r,o){a(o||n.d,i,e,t,r)}function a(e,t,r,i,o){o||(o="feature"),e||(e=n.d);var a=t[o]=t[o]||{};(a[r]=a[r]||[]).push([e,i])}},878:(e,t,r)=>{"use strict";function n(e,t){return{capture:e,passive:!1,signal:t}}function i(e,t,r=!1,i){window.addEventListener(e,t,n(r,i))}function o(e,t,r=!1,i){document.addEventListener(e,t,n(r,i))}r.d(t,{DD:()=>o,jT:()=>n,sp:()=>i})},607:(e,t,r)=>{"use strict";r.d(t,{W:()=>n});const n=(0,r(566).bz)()},566:(e,t,r)=>{"use strict";r.d(t,{LA:()=>s,bz:()=>a});var n=r(154);const i="xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx";function o(e,t){return e?15&e[t]:16*Math.random()|0}function a(){const e=n.gm?.crypto||n.gm?.msCrypto;let t,r=0;return e&&e.getRandomValues&&(t=e.getRandomValues(new Uint8Array(30))),i.split("").map((e=>"x"===e?o(t,r++).toString(16):"y"===e?(3&o()|8).toString(16):e)).join("")}function s(e){const t=n.gm?.crypto||n.gm?.msCrypto;let r,i=0;t&&t.getRandomValues&&(r=t.getRandomValues(new Uint8Array(e)));const a=[];for(var s=0;s<e;s++)a.push(o(r,i++).toString(16));return a.join("")}},614:(e,t,r)=>{"use strict";r.d(t,{BB:()=>a,H3:()=>n,g:()=>u,iL:()=>c,tS:()=>s,uh:()=>i,wk:()=>o});const n="NRBA",i="SESSION",o=144e5,a=18e5,s={STARTED:"session-started",PAUSE:"session-pause",RESET:"session-reset",RESUME:"session-resume",UPDATE:"session-update"},c={SAME_TAB:"same-tab",CROSS_TAB:"cross-tab"},u={OFF:0,FULL:1,ERROR:2}},863:(e,t,r)=>{"use strict";function n(){return Math.floor(performance.now())}r.d(t,{t:()=>n})},944:(e,t,r)=>{"use strict";function n(e,t){"function"==typeof console.debug&&console.debug("New Relic Warning: https://github.com/newrelic/newrelic-browser-agent/blob/main/docs/warning-codes.md#".concat(e),t)}r.d(t,{R:()=>n})},284:(e,t,r)=>{"use strict";r.d(t,{t:()=>c,B:()=>s});var n=r(836),i=r(154);const o="newrelic";const a=new Set,s={};function c(e,t){const r=n.ee.get(t);s[t]??={},e&&"object"==typeof e&&(a.has(t)||(r.emit("rumresp",[e]),s[t]=e,a.add(t),function(e={}){try{i.gm.dispatchEvent(new CustomEvent(o,{detail:e}))}catch(e){}}({loaded:!0})))}},990:(e,t,r)=>{"use strict";r.d(t,{I:()=>i});var n=Object.prototype.hasOwnProperty;function i(e,t,r){if(n.call(e,t))return e[t];var i=r();if(Object.defineProperty&&Object.keys)try{return Object.defineProperty(e,t,{value:i,writable:!0,enumerable:!1}),i}catch(e){}return e[t]=i,i}},389:(e,t,r)=>{"use strict";function n(e,t=500,r={}){const n=r?.leading||!1;let i;return(...r)=>{n&&void 0===i&&(e.apply(this,r),i=setTimeout((()=>{i=clearTimeout(i)}),t)),n||(clearTimeout(i),i=setTimeout((()=>{e.apply(this,r)}),t))}}function i(e){let t=!1;return(...r)=>{t||(t=!0,e.apply(this,r))}}r.d(t,{J:()=>i,s:()=>n})},289:(e,t,r)=>{"use strict";r.d(t,{GG:()=>o,sB:()=>a});var n=r(878);function i(){return"undefined"==typeof document||"complete"===document.readyState}function o(e,t){if(i())return e();(0,n.sp)("load",e,t)}function a(e){if(i())return e();(0,n.DD)("DOMContentLoaded",e)}},384:(e,t,r)=>{"use strict";r.d(t,{NT:()=>o,US:()=>l,Zm:()=>a,bQ:()=>c,dV:()=>s,nY:()=>u,pV:()=>d});var n=r(154),i=r(863);const o={beacon:"bam.nr-data.net",errorBeacon:"bam.nr-data.net"};function a(){return n.gm.NREUM||(n.gm.NREUM={}),void 0===n.gm.newrelic&&(n.gm.newrelic=n.gm.NREUM),n.gm.NREUM}function s(){let e=a();return e.o||(e.o={ST:n.gm.setTimeout,SI:n.gm.setImmediate,CT:n.gm.clearTimeout,XHR:n.gm.XMLHttpRequest,REQ:n.gm.Request,EV:n.gm.Event,PR:n.gm.Promise,MO:n.gm.MutationObserver,FETCH:n.gm.fetch,WS:n.gm.WebSocket}),e}function c(e,t){let r=a();r.initializedAgents??={},t.initializedAt={ms:(0,i.t)(),date:new Date},r.initializedAgents[e]=t}function u(e){let t=a();return t.initializedAgents?.[e]}function l(e,t){a()[e]=t}function d(){return function(){let e=a();const t=e.info||{};e.info={beacon:o.beacon,errorBeacon:o.errorBeacon,...t}}(),function(){let e=a();const t=e.init||{};e.init={...t}}(),s(),function(){let e=a();const t=e.loader_config||{};e.loader_config={...t}}(),a()}},843:(e,t,r)=>{"use strict";r.d(t,{u:()=>i});var n=r(878);function i(e,t=!1,r,i){(0,n.DD)("visibilitychange",(function(){if(t)return void("hidden"===document.visibilityState&&e());e(document.visibilityState)}),r,i)}},434:(e,t,r)=>{"use strict";r.d(t,{Jt:()=>o,YM:()=>c});var n=r(836),i=r(607);const o="nr@original:".concat(i.W);var a=Object.prototype.hasOwnProperty,s=!1;function c(e,t){return e||(e=n.ee),r.inPlace=function(e,t,n,i,o){n||(n="");const a="-"===n.charAt(0);for(let s=0;s<t.length;s++){const c=t[s],u=e[c];l(u)||(e[c]=r(u,a?c+n:n,i,c,o))}},r.flag=o,r;function r(t,r,n,s,c){return l(t)?t:(r||(r=""),nrWrapper[o]=t,function(e,t,r){if(Object.defineProperty&&Object.keys)try{return Object.keys(e).forEach((function(r){Object.defineProperty(t,r,{get:function(){return e[r]},set:function(t){return e[r]=t,t}})})),t}catch(e){u([e],r)}for(var n in e)a.call(e,n)&&(t[n]=e[n])}(t,nrWrapper,e),nrWrapper);function nrWrapper(){var o,a,l,d;try{a=this,o=[...arguments],l="function"==typeof n?n(o,a):n||{}}catch(t){u([t,"",[o,a,s],l],e)}i(r+"start",[o,a,s],l,c);try{return d=t.apply(a,o)}catch(e){throw i(r+"err",[o,a,e],l,c),e}finally{i(r+"end",[o,a,d],l,c)}}}function i(r,n,i,o){if(!s||t){var a=s;s=!0;try{e.emit(r,n,i,t,o)}catch(t){u([t,r,n,i],e)}s=a}}}function u(e,t){t||(t=n.ee);try{t.emit("internal-error",e)}catch(e){}}function l(e){return!(e&&"function"==typeof e&&e.apply&&!e[o])}},993:(e,t,r)=>{"use strict";r.d(t,{A$:()=>o,ET:()=>a,p_:()=>i});var n=r(860);const i={ERROR:"ERROR",WARN:"WARN",INFO:"INFO",DEBUG:"DEBUG",TRACE:"TRACE"},o={OFF:0,ERROR:1,WARN:2,INFO:3,DEBUG:4,TRACE:5},a="log";n.K7.logging},773:(e,t,r)=>{"use strict";r.d(t,{z_:()=>o,XG:()=>s,TZ:()=>n,rs:()=>i,xV:()=>a});r(154),r(566),r(384);const n=r(860).K7.metrics,i="sm",o="cm",a="storeSupportabilityMetrics",s="storeEventMetrics"},630:(e,t,r)=>{"use strict";r.d(t,{T:()=>n});const n=r(860).K7.pageViewEvent},782:(e,t,r)=>{"use strict";r.d(t,{T:()=>n});const n=r(860).K7.pageViewTiming},344:(e,t,r)=>{"use strict";r.d(t,{G4:()=>i});var n=r(614);r(860).K7.sessionReplay;const i={RECORD:"recordReplay",PAUSE:"pauseReplay",REPLAY_RUNNING:"replayRunning",ERROR_DURING_REPLAY:"errorDuringReplay"};n.g.ERROR,n.g.FULL,n.g.OFF},234:(e,t,r)=>{"use strict";r.d(t,{W:()=>o});var n=r(836),i=r(687);class o{constructor(e,t){this.agentIdentifier=e,this.ee=n.ee.get(e),this.featureName=t,this.blocked=!1}deregisterDrain(){(0,i.x3)(this.agentIdentifier,this.featureName)}}},603:(e,t,r)=>{"use strict";r.d(t,{j:()=>K});var n=r(860),i=r(555),o=r(371),a=r(908),s=r(836),c=r(687),u=r(289),l=r(154),d=r(944),f=r(773),g=r(384),p=r(344);const m=["setErrorHandler","finished","addToTrace","addRelease","recordCustomEvent","addPageAction","setCurrentRouteName","setPageViewName","setCustomAttribute","interaction","noticeError","setUserId","setApplicationVersion","start",p.G4.RECORD,p.G4.PAUSE,"log","wrapLogger"],h=["setErrorHandler","finished","addToTrace","addRelease"];var v=r(863),b=r(614),y=r(993);var w=r(646),R=r(434);const A=new Map;function E(e,t,r,n){if("object"!=typeof t||!t||"string"!=typeof r||!r||"function"!=typeof t[r])return(0,d.R)(29);const i=function(e){return(e||s.ee).get("logger")}(e),o=(0,R.YM)(i),a=new w.y(s.P);a.level=n.level,a.customAttributes=n.customAttributes;const c=t[r]?.[R.Jt]||t[r];return A.set(c,a),o.inPlace(t,[r],"wrap-logger-",(()=>A.get(c))),i}function _(){const e=(0,g.pV)();m.forEach((t=>{e[t]=(...r)=>function(t,...r){let n=[];return Object.values(e.initializedAgents).forEach((e=>{e&&e.api?e.exposed&&e.api[t]&&n.push(e.api[t](...r)):(0,d.R)(38,t)})),n.length>1?n:n[0]}(t,...r)}))}const x={};function N(e,t,g=!1){t||(0,c.Ak)(e,"api");const m={};var w=s.ee.get(e),R=w.get("tracer");x[e]=b.g.OFF,w.on(p.G4.REPLAY_RUNNING,(t=>{x[e]=t}));var A="api-",_=A+"ixn-";function N(t,r,n,o){const a=(0,i.Vp)(e);return null===r?delete a.jsAttributes[t]:(0,i.x1)(e,{...a,jsAttributes:{...a.jsAttributes,[t]:r}}),j(A,n,!0,o||null===r?"session":void 0)(t,r)}function k(){}m.log=function(e,{customAttributes:t={},level:r=y.p_.INFO}={}){(0,a.p)(f.xV,["API/log/called"],void 0,n.K7.metrics,w),function(e,t,r={},i=y.p_.INFO){(0,a.p)(f.xV,["API/logging/".concat(i.toLowerCase(),"/called")],void 0,n.K7.metrics,e),(0,a.p)(y.ET,[(0,v.t)(),t,r,i],void 0,n.K7.logging,e)}(w,e,t,r)},m.wrapLogger=(e,t,{customAttributes:r={},level:i=y.p_.INFO}={})=>{(0,a.p)(f.xV,["API/wrapLogger/called"],void 0,n.K7.metrics,w),E(w,e,t,{customAttributes:r,level:i})},h.forEach((e=>{m[e]=j(A,e,!0,"api")})),m.addPageAction=j(A,"addPageAction",!0,n.K7.genericEvents),m.recordCustomEvent=j(A,"recordCustomEvent",!0,n.K7.genericEvents),m.setPageViewName=function(t,r){if("string"==typeof t)return"/"!==t.charAt(0)&&(t="/"+t),(0,o.f)(e).customTransaction=(r||"http://custom.transaction")+t,j(A,"setPageViewName",!0)()},m.setCustomAttribute=function(e,t,r=!1){if("string"==typeof e){if(["string","number","boolean"].includes(typeof t)||null===t)return N(e,t,"setCustomAttribute",r);(0,d.R)(40,typeof t)}else(0,d.R)(39,typeof e)},m.setUserId=function(e){if("string"==typeof e||null===e)return N("enduser.id",e,"setUserId",!0);(0,d.R)(41,typeof e)},m.setApplicationVersion=function(e){if("string"==typeof e||null===e)return N("application.version",e,"setApplicationVersion",!1);(0,d.R)(42,typeof e)},m.start=()=>{try{(0,a.p)(f.xV,["API/start/called"],void 0,n.K7.metrics,w),w.emit("manual-start-all")}catch(e){(0,d.R)(23,e)}},m[p.G4.RECORD]=function(){(0,a.p)(f.xV,["API/recordReplay/called"],void 0,n.K7.metrics,w),(0,a.p)(p.G4.RECORD,[],void 0,n.K7.sessionReplay,w)},m[p.G4.PAUSE]=function(){(0,a.p)(f.xV,["API/pauseReplay/called"],void 0,n.K7.metrics,w),(0,a.p)(p.G4.PAUSE,[],void 0,n.K7.sessionReplay,w)},m.interaction=function(e){return(new k).get("object"==typeof e?e:{})};const T=k.prototype={createTracer:function(e,t){var r={},i=this,o="function"==typeof t;return(0,a.p)(f.xV,["API/createTracer/called"],void 0,n.K7.metrics,w),g||(0,a.p)(_+"tracer",[(0,v.t)(),e,r],i,n.K7.spa,w),function(){if(R.emit((o?"":"no-")+"fn-start",[(0,v.t)(),i,o],r),o)try{return t.apply(this,arguments)}catch(e){const t="string"==typeof e?new Error(e):e;throw R.emit("fn-err",[arguments,this,t],r),t}finally{R.emit("fn-end",[(0,v.t)()],r)}}}};function j(e,t,r,i){return function(){return(0,a.p)(f.xV,["API/"+t+"/called"],void 0,n.K7.metrics,w),i&&(0,a.p)(e+t,[r?(0,v.t)():performance.now(),...arguments],r?null:this,i,w),r?void 0:this}}function I(){r.e(296).then(r.bind(r,778)).then((({setAPI:t})=>{t(e),(0,c.Ze)(e,"api")})).catch((e=>{(0,d.R)(27,e),w.abort()}))}return["actionText","setName","setAttribute","save","ignore","onEnd","getContext","end","get"].forEach((e=>{T[e]=j(_,e,void 0,g?n.K7.softNav:n.K7.spa)})),m.setCurrentRouteName=g?j(_,"routeName",void 0,n.K7.softNav):j(A,"routeName",!0,n.K7.spa),m.noticeError=function(t,r){"string"==typeof t&&(t=new Error(t)),(0,a.p)(f.xV,["API/noticeError/called"],void 0,n.K7.metrics,w),(0,a.p)("err",[t,(0,v.t)(),!1,r,!!x[e]],void 0,n.K7.jserrors,w)},l.RI?(0,u.GG)((()=>I()),!0):I(),m}var k=r(217),T=r(122);const j={accountID:void 0,trustKey:void 0,agentID:void 0,licenseKey:void 0,applicationID:void 0,xpid:void 0},I={};var O=r(284);const S=e=>{const t=e.startsWith("http");e+="/",r.p=t?e:"https://"+e};let P=!1;function K(e,t={},r,n){let{init:a,info:c,loader_config:u,runtime:d={},exposed:f=!0}=t;d.loaderType=r;const p=(0,g.pV)();c||(a=p.init,c=p.info,u=p.loader_config),(0,k.xN)(e.agentIdentifier,a||{}),function(e,t){if(!e)throw new Error("All loader-config objects require an agent identifier!");I[e]=(0,T.a)(t,j);const r=(0,g.nY)(e);r&&(r.loader_config=I[e])}(e.agentIdentifier,u||{}),c.jsAttributes??={},l.bv&&(c.jsAttributes.isWorker=!0),(0,i.x1)(e.agentIdentifier,c);const m=(0,k.D0)(e.agentIdentifier),h=[c.beacon,c.errorBeacon];P||(m.proxy.assets&&(S(m.proxy.assets),h.push(m.proxy.assets)),m.proxy.beacon&&h.push(m.proxy.beacon),_(),(0,g.US)("activatedFeatures",O.B),e.runSoftNavOverSpa&&=!0===m.soft_navigations.enabled&&m.feature_flags.includes("soft_nav")),d.denyList=[...m.ajax.deny_list||[],...m.ajax.block_internal?h:[]],d.ptid=e.agentIdentifier,(0,o.V)(e.agentIdentifier,d),e.ee=s.ee.get(e.agentIdentifier),void 0===e.api&&(e.api=N(e.agentIdentifier,n,e.runSoftNavOverSpa)),void 0===e.exposed&&(e.exposed=f),P=!0}},374:(e,t,r)=>{r.nc=(()=>{try{return document?.currentScript?.nonce}catch(e){}return""})()},860:(e,t,r)=>{"use strict";r.d(t,{$J:()=>u,K7:()=>s,P3:()=>c,XX:()=>i,qY:()=>n,v4:()=>a});const n="events",i="jserrors",o="browser/blobs",a="rum",s={ajax:"ajax",genericEvents:"generic_events",jserrors:i,logging:"logging",metrics:"metrics",pageAction:"page_action",pageViewEvent:"page_view_event",pageViewTiming:"page_view_timing",sessionReplay:"session_replay",sessionTrace:"session_trace",softNav:"soft_navigations",spa:"spa"},c={[s.pageViewEvent]:1,[s.pageViewTiming]:2,[s.metrics]:3,[s.jserrors]:4,[s.spa]:5,[s.ajax]:6,[s.sessionTrace]:7,[s.softNav]:8,[s.sessionReplay]:9,[s.logging]:10,[s.genericEvents]:11},u={[s.pageViewEvent]:a,[s.pageViewTiming]:n,[s.ajax]:n,[s.spa]:n,[s.softNav]:n,[s.metrics]:i,[s.jserrors]:i,[s.sessionTrace]:o,[s.sessionReplay]:o,[s.logging]:"browser/logs",[s.genericEvents]:"ins"}}},n={};function i(e){var t=n[e];if(void 0!==t)return t.exports;var o=n[e]={exports:{}};return r[e](o,o.exports,i),o.exports}i.m=r,i.d=(e,t)=>{for(var r in t)i.o(t,r)&&!i.o(e,r)&&Object.defineProperty(e,r,{enumerable:!0,get:t[r]})},i.f={},i.e=e=>Promise.all(Object.keys(i.f).reduce(((t,r)=>(i.f[r](e,t),t)),[])),i.u=e=>"nr-rum-1.283.2.min.js",i.o=(e,t)=>Object.prototype.hasOwnProperty.call(e,t),e={},t="NRBA-1.283.2.PROD:",i.l=(r,n,o,a)=>{if(e[r])e[r].push(n);else{var s,c;if(void 0!==o)for(var u=document.getElementsByTagName("script"),l=0;l<u.length;l++){var d=u[l];if(d.getAttribute("src")==r||d.getAttribute("data-webpack")==t+o){s=d;break}}if(!s){c=!0;var f={296:"sha512-2Y8GMAOGF658KnXzOZ/v+DlLch8TBFvV0tTNnOy9wrpvtDa1t5CdZMyX+LubTymBlzPp6NUjllBghMCZqXBPmg=="};(s=document.createElement("script")).charset="utf-8",s.timeout=120,i.nc&&s.setAttribute("nonce",i.nc),s.setAttribute("data-webpack",t+o),s.src=r,0!==s.src.indexOf(window.location.origin+"/")&&(s.crossOrigin="anonymous"),f[a]&&(s.integrity=f[a])}e[r]=[n];var g=(t,n)=>{s.onerror=s.onload=null,clearTimeout(p);var i=e[r];if(delete e[r],s.parentNode&&s.parentNode.removeChild(s),i&&i.forEach((e=>e(n))),t)return t(n)},p=setTimeout(g.bind(null,void 0,{type:"timeout",target:s}),12e4);s.onerror=g.bind(null,s.onerror),s.onload=g.bind(null,s.onload),c&&document.head.appendChild(s)}},i.r=e=>{"undefined"!=typeof Symbol&&Symbol.toStringTag&&Object.defineProperty(e,Symbol.toStringTag,{value:"Module"}),Object.defineProperty(e,"__esModule",{value:!0})},i.p="https://js-agent.newrelic.com/",(()=>{var e={374:0,840:0};i.f.j=(t,r)=>{var n=i.o(e,t)?e[t]:void 0;if(0!==n)if(n)r.push(n[2]);else{var o=new Promise(((r,i)=>n=e[t]=[r,i]));r.push(n[2]=o);var a=i.p+i.u(t),s=new Error;i.l(a,(r=>{if(i.o(e,t)&&(0!==(n=e[t])&&(e[t]=void 0),n)){var o=r&&("load"===r.type?"missing":r.type),a=r&&r.target&&r.target.src;s.message="Loading chunk "+t+" failed.\n("+o+": "+a+")",s.name="ChunkLoadError",s.type=o,s.request=a,n[1](s)}}),"chunk-"+t,t)}};var t=(t,r)=>{var n,o,[a,s,c]=r,u=0;if(a.some((t=>0!==e[t]))){for(n in s)i.o(s,n)&&(i.m[n]=s[n]);if(c)c(i)}for(t&&t(r);u<a.length;u++)o=a[u],i.o(e,o)&&e[o]&&e[o][0](),e[o]=0},r=self["webpackChunk:NRBA-1.283.2.PROD"]=self["webpackChunk:NRBA-1.283.2.PROD"]||[];r.forEach(t.bind(null,0)),r.push=t.bind(null,r.push.bind(r))})(),(()=>{"use strict";i(374);var e=i(944),t=i(344),r=i(566);class n{agentIdentifier;constructor(){this.agentIdentifier=(0,r.LA)(16)}#e(t,...r){if("function"==typeof this.api?.[t])return this.api[t](...r);(0,e.R)(35,t)}addPageAction(e,t){return this.#e("addPageAction",e,t)}recordCustomEvent(e,t){return this.#e("recordCustomEvent",e,t)}setPageViewName(e,t){return this.#e("setPageViewName",e,t)}setCustomAttribute(e,t,r){return this.#e("setCustomAttribute",e,t,r)}noticeError(e,t){return this.#e("noticeError",e,t)}setUserId(e){return this.#e("setUserId",e)}setApplicationVersion(e){return this.#e("setApplicationVersion",e)}setErrorHandler(e){return this.#e("setErrorHandler",e)}addRelease(e,t){return this.#e("addRelease",e,t)}log(e,t){return this.#e("log",e,t)}}class o extends n{#e(t,...r){if("function"==typeof this.api?.[t])return this.api[t](...r);(0,e.R)(35,t)}start(){return this.#e("start")}finished(e){return this.#e("finished",e)}recordReplay(){return this.#e(t.G4.RECORD)}pauseReplay(){return this.#e(t.G4.PAUSE)}addToTrace(e){return this.#e("addToTrace",e)}setCurrentRouteName(e){return this.#e("setCurrentRouteName",e)}interaction(){return this.#e("interaction")}wrapLogger(e,t,r){return this.#e("wrapLogger",e,t,r)}}var a=i(860),s=i(217);const c=Object.values(a.K7);function u(e){const t={};return c.forEach((r=>{t[r]=function(e,t){return!0===(0,s.gD)(t,"".concat(e,".enabled"))}(r,e)})),t}var l=i(603);var d=i(687),f=i(234),g=i(289),p=i(154),m=i(384);const h=e=>p.RI&&!0===(0,s.gD)(e,"privacy.cookies_enabled");function v(e){return!!(0,m.dV)().o.MO&&h(e)&&!0===(0,s.gD)(e,"session_trace.enabled")}var b=i(389);class y extends f.W{constructor(e,t,r=!0){super(e.agentIdentifier,t),this.auto=r,this.abortHandler=void 0,this.featAggregate=void 0,this.onAggregateImported=void 0,!1===e.init[this.featureName].autoStart&&(this.auto=!1),this.auto?(0,d.Ak)(e.agentIdentifier,t):this.ee.on("manual-start-all",(0,b.J)((()=>{(0,d.Ak)(e.agentIdentifier,this.featureName),this.auto=!0,this.importAggregator(e)})))}importAggregator(t,r={}){if(this.featAggregate||!this.auto)return;let n;this.onAggregateImported=new Promise((e=>{n=e}));const o=async()=>{let o;try{if(h(this.agentIdentifier)){const{setupAgentSession:e}=await i.e(296).then(i.bind(i,861));o=e(t)}}catch(t){(0,e.R)(20,t),this.ee.emit("internal-error",[t]),this.featureName===a.K7.sessionReplay&&this.abortHandler?.()}try{if(!this.#t(this.featureName,o))return(0,d.Ze)(this.agentIdentifier,this.featureName),void n(!1);const{lazyFeatureLoader:e}=await i.e(296).then(i.bind(i,103)),{Aggregate:a}=await e(this.featureName,"aggregate");this.featAggregate=new a(t,r),t.runtime.harvester.initializedAggregates.push(this.featAggregate),n(!0)}catch(t){(0,e.R)(34,t),this.abortHandler?.(),(0,d.Ze)(this.agentIdentifier,this.featureName,!0),n(!1),this.ee&&this.ee.abort()}};p.RI?(0,g.GG)((()=>o()),!0):o()}#t(e,t){switch(e){case a.K7.sessionReplay:return v(this.agentIdentifier)&&!!t;case a.K7.sessionTrace:return!!t;default:return!0}}}var w=i(630);class R extends y{static featureName=w.T;constructor(e,t=!0){super(e,w.T,t),this.importAggregator(e)}}var A=i(908),E=i(843),_=i(878),x=i(782),N=i(863);class k extends y{static featureName=x.T;constructor(e,t=!0){super(e,x.T,t),p.RI&&((0,E.u)((()=>(0,A.p)("docHidden",[(0,N.t)()],void 0,x.T,this.ee)),!0),(0,_.sp)("pagehide",(()=>(0,A.p)("winPagehide",[(0,N.t)()],void 0,x.T,this.ee))),this.importAggregator(e))}}var T=i(773);class j extends y{static featureName=T.TZ;constructor(e,t=!0){super(e,T.TZ,t),this.importAggregator(e)}}new class extends o{constructor(t){super(),p.gm?(this.features={},(0,m.bQ)(this.agentIdentifier,this),this.desiredFeatures=new Set(t.features||[]),this.desiredFeatures.add(R),this.runSoftNavOverSpa=[...this.desiredFeatures].some((e=>e.featureName===a.K7.softNav)),(0,l.j)(this,t,t.loaderType||"agent"),this.run()):(0,e.R)(21)}get config(){return{info:this.info,init:this.init,loader_config:this.loader_config,runtime:this.runtime}}run(){try{const t=u(this.agentIdentifier),r=[...this.desiredFeatures];r.sort(((e,t)=>a.P3[e.featureName]-a.P3[t.featureName])),r.forEach((r=>{if(!t[r.featureName]&&r.featureName!==a.K7.pageViewEvent)return;if(this.runSoftNavOverSpa&&r.featureName===a.K7.spa)return;if(!this.runSoftNavOverSpa&&r.featureName===a.K7.softNav)return;const n=function(e){switch(e){case a.K7.ajax:return[a.K7.jserrors];case a.K7.sessionTrace:return[a.K7.ajax,a.K7.pageViewEvent];case a.K7.sessionReplay:return[a.K7.sessionTrace];case a.K7.pageViewTiming:return[a.K7.pageViewEvent];default:return[]}}(r.featureName).filter((e=>!(e in this.features)));n.length>0&&(0,e.R)(36,{targetFeature:r.featureName,missingDependencies:n}),this.features[r.featureName]=new r(this)}))}catch(t){(0,e.R)(22,t);for(const e in this.features)this.features[e].abortHandler?.();const r=(0,m.Zm)();delete r.initializedAgents[this.agentIdentifier]?.api,delete r.initializedAgents[this.agentIdentifier]?.features,delete this.sharedAggregator;return r.ee.get(this.agentIdentifier).abort(),!1}}}({features:[R,k,j],loaderType:"lite"})})()})();</script>
<noscript><style>form.antibot * :not(.antibot-message) { display: none !important; }</style>
</noscript><script async src="https://www.googletagmanager.com/gtag/js?id=G-HEQ0YF2VYL"></script>
<script>window.dataLayer = window.dataLayer || [];function gtag(){dataLayer.push(arguments)};gtag("js", new Date());gtag("set", "developer_id.dMDhkMT", true);gtag('set', {'cookie_flags': 'SameSite=None;Secure', 'cookie_domain': 'www.nist.gov'});gtag("config", "G-HEQ0YF2VYL", {"groups":"default","page_placeholder":"PLACEHOLDER_page_location","link_attribution":true,"allow_ad_personalization_signals":false});gtag("config", "G-CSLL4ZEK4L", {"groups":"default","page_placeholder":"PLACEHOLDER_page_location","link_attribution":true,"allow_ad_personalization_signals":false});gtag("event", "custom", {"node_title":"Taking a Seat at the Periodic Table","node_id":"1246736","blog_author":"Michael E. Newman","content_type":"Blog entry"});</script>
<meta name="description" content="In case you haven’t already heard, if you wanted to give your loved one that special, once-in-a-lifetime gift by naming one of the elements in row 7 of the P" />
<link rel="canonical" href="https://www.nist.gov/blogs/taking-measure/taking-seat-periodic-table" />
<link rel="shortlink" href="https://www.nist.gov/node/1246736" />
<meta name="citation_title" content="Taking a Seat at the Periodic Table | NIST" />
<meta property="og:site_name" content="NIST" />
<meta property="og:type" content="Article" />
<meta property="og:url" content="https://www.nist.gov/blogs/taking-measure/taking-seat-periodic-table" />
<meta property="og:title" content="Taking a Seat at the Periodic Table" />
<meta property="og:description" content="In case you haven’t already heard, if you wanted to give your loved one that special, once-in-a-lifetime gift by naming one of the elements in row 7 of the P" />
<meta property="og:image" content="https://www.nist.gov/sites/default/files/styles/social/public/images/2017/11/08/Element-117.jpg?itok=mDUI0G84" />
<meta property="og:image" content="https://www.nist.gov/themes/custom/nist_www/img/homepage/nist_mark.png" />
<meta property="og:image:width" content="1920" />
<meta property="og:image:height" content="1080" />
<meta property="og:image:alt" content="Roundish shape clear ball containing multiple round-ish shapes with red or orange centers" />
<meta property="article:author" content="Michael E. Newman" />
<meta property="article:published_time" content="2017-02-07T07:00-05:00" />
<meta property="article:modified_time" content="2025-01-24T09:37-05:00" />
<meta name="dcterms.title" content="Taking a Seat at the Periodic Table" />
<meta name="dcterms.creator" content="Michael E. Newman" />
<meta name="dcterms.description" content="In case you haven’t already heard, if you wanted to give your loved one that special, once-in-a-lifetime gift by naming one of the elements in row 7 of the P" />
<meta name="dcterms.publisher" content="Michael E. Newman" />
<meta name="dcterms.contributor" content="NIST" />
<meta name="dcterms.date" content="2017-02-07T07:00-05:00" />
<meta name="dcterms.type" content="text" />
<meta name="dcterms.format" content="text/html" />
<meta name="dcterms.identifier" content="https://www.nist.gov/blogs/taking-measure/taking-seat-periodic-table" />
<meta name="dcterms.source" content="NIST" />
<meta name="dcterms.created" content="2017-02-07T07:00-05:00" />
<meta name="dcterms.modified" content="2025-01-24T09:37-05:00" />
<meta name="twitter:card" content="summary_large_image" />
<meta name="twitter:description" content="In case you haven’t already heard, if you wanted to give your loved one that special, once-in-a-lifetime gift by naming one of the elements in row 7 of the P" />
<meta name="twitter:site" content="NIST" />
<meta name="twitter:title" content="Taking a Seat at the Periodic Table" />
<meta name="google-site-verification" content="QMu0ODkER3rN5hLcMLqNVf7e3bkjYsNLTuhqfH48jCA" />
<meta name="Generator" content="Drupal 10 (https://www.drupal.org)" />
<meta name="MobileOptimized" content="width" />
<meta name="HandheldFriendly" content="true" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<meta name="nist_search_modified" class="elastic" content="2025-01-24T09:37:00-05:00" />
<script type="application/ld+json">{
"@context": "https://schema.org",
"@graph": [
{
"@type": "Article",
"@id": "https://www.nist.gov/blogs/taking-measure/taking-seat-periodic-table",
"headline": "Taking a Seat at the Periodic Table",
"name": "Taking a Seat at the Periodic Table",
"description": "In case you haven’t already heard, if you wanted to give your loved one that special, once-in-a-lifetime gift by naming one of the elements in row 7 of the P",
"image": {
"@type": "ImageObject",
"url": "https://www.nist.gov/sites/default/files/styles/social/public/images/2017/11/08/Element-117.jpg?itok=mDUI0G84",
"width": "1920",
"height": "1080"
},
"datePublished": "2017-02-07T07:00-05:00",
"dateModified": "2025-01-24T09:37-05:00",
"author": {
"@type": "Person",
"@id": "https://www.nist.gov/blogs/taking-measure/authors/michael-e-newman",
"name": "Michael E. Newman",
"url": "https://www.nist.gov/blogs/taking-measure/authors/michael-e-newman"
},
"publisher": {
"@type": "GovernmentOrganization",
"@id": "https://www.nist.gov/",
"name": "National Institute of Standards and Technology",
"url": "https://www.nist.gov/"
}
}
]
}</script>
<meta name="nist_search_bundle" class="elastic" content="blog" />
<link rel="icon" href="/themes/custom/nist_www/favicon.ico" type="image/vnd.microsoft.icon" />
<title>Taking a Seat at the Periodic Table | NIST</title>
<link rel="stylesheet" media="all" href="/sites/default/files/css/css_hKAD9a0878O1Pdb6alKtCmESLiUtQmrBX15rQUvSgOA.css?delta=0&amp;language=en&amp;theme=nist_www&amp;include=eJxNTgsOwyAIvZCpRzKotCNFaYTW9fazW5ctIYRH3i9CWoPJmM3H3x0oSXWV1II9sOD4CUdooUj2mRQiY2Cqq9NTDcvQKr75fmGJwB9t7_2L8WkX3-e2b8DTDd1B2NW_9zS8d75dCiyVZkpuJjZsPsFmNCqpJAIOBTPBFToYDKfsFkarJAe200vFJH8NCqUmSoYvWkVdRQ" />
<link rel="stylesheet" media="all" href="/sites/default/files/css/css_kGS0ApDpFo-_3JI4Ijxg4RCWlTqsImK3lqH7bCv5v2U.css?delta=1&amp;language=en&amp;theme=nist_www&amp;include=eJxNTgsOwyAIvZCpRzKotCNFaYTW9fazW5ctIYRH3i9CWoPJmM3H3x0oSXWV1II9sOD4CUdooUj2mRQiY2Cqq9NTDcvQKr75fmGJwB9t7_2L8WkX3-e2b8DTDd1B2NW_9zS8d75dCiyVZkpuJjZsPsFmNCqpJAIOBTPBFToYDKfsFkarJAe200vFJH8NCqUmSoYvWkVdRQ" />
<link rel="stylesheet" media="print" href="/sites/default/files/css/css_-IXwLuTUdm8IGHxib8GX8wWKw3LjKsNWSYYskZ5fEGg.css?delta=2&amp;language=en&amp;theme=nist_www&amp;include=eJxNTgsOwyAIvZCpRzKotCNFaYTW9fazW5ctIYRH3i9CWoPJmM3H3x0oSXWV1II9sOD4CUdooUj2mRQiY2Cqq9NTDcvQKr75fmGJwB9t7_2L8WkX3-e2b8DTDd1B2NW_9zS8d75dCiyVZkpuJjZsPsFmNCqpJAIOBTPBFToYDKfsFkarJAe200vFJH8NCqUmSoYvWkVdRQ" />
<link rel="stylesheet" media="all" href="/sites/default/files/css/css_RS8YGnRq2Xi5aD-GQC3GKwBe6bOWBBmEmXrb2xB5FMM.css?delta=3&amp;language=en&amp;theme=nist_www&amp;include=eJxNTgsOwyAIvZCpRzKotCNFaYTW9fazW5ctIYRH3i9CWoPJmM3H3x0oSXWV1II9sOD4CUdooUj2mRQiY2Cqq9NTDcvQKr75fmGJwB9t7_2L8WkX3-e2b8DTDd1B2NW_9zS8d75dCiyVZkpuJjZsPsFmNCqpJAIOBTPBFToYDKfsFkarJAe200vFJH8NCqUmSoYvWkVdRQ" />
<script src="/sites/default/files/js/js_GM8kl6wk698qKTTwusj83bCoGHHtOZ1UinjY1sE_Qbk.js?scope=header&amp;delta=0&amp;language=en&amp;theme=nist_www&amp;include=eJxdjWsSgyAMhC-kzZEyQSKmAnEApb198dFpx5n8yLfJ7hoaZizaZgHz2_GZO6fqPCNF8u8iQ4a70EXJBUdpmtUavZLFklqIRAeOznOWwhKWpBvDXdhbDq1MHLj1qjeUMKgFK5lMC_YS5-MHnFdDvr8sMDFZTl_EWuvfB7_KbgSb1oX848LTGMhFGWXoNuGa8bmGBQPHFQ7ud-53_gAS9G-N"></script>
</head>
<body class="node-1246736">
<a href="#main-content" class="visually-hidden focusable" data-elastic-exclude>
Skip to main content
</a>
<div class="dialog-off-canvas-main-canvas" data-off-canvas-main-canvas>
<!-- nist-index-ignore-start -->
<section data-elastic-exclude class="usa-banner" aria-label="Official government website">
<div class="usa-accordion">
<header class="usa-banner__header">
<div class="usa-banner__inner">
<div class="grid-col-auto">
<img class="usa-banner__header-flag" src="/libraries/nist-component-library/dist/img/us_flag_small.png" alt="U.S. flag">
</div>
<div class="grid-col-fill tablet:grid-col-auto">
<p class="usa-banner__header-text">An official website of the United States government</p>
<p class="usa-banner__header-action" aria-hidden="true">Here’s how you know</p>
</div>
<button class="usa-accordion__button usa-banner__button" aria-expanded="false" aria-controls="gov-banner-default">
<span class="usa-banner__button-text">Here’s how you know</span>
</button>
</div>
</header>
<div class="usa-banner__content usa-accordion__content" id="gov-banner-default">
<div class="grid-row grid-gap-lg">
<div class="usa-banner__guidance tablet:grid-col-6">
<img class="usa-banner__icon usa-media-block__img" src="/libraries/nist-component-library/dist/img/icon-dot-gov.svg" role="img" alt="" aria-hidden="true">
<div class="usa-media-block__body">
<p>
<strong>Official websites use .gov</strong>
<br/>
A <strong>.gov</strong> website belongs to an official government organization in the United States.
</p>
</div>
</div>
<div class="usa-banner__guidance tablet:grid-col-6">
<img class="usa-banner__icon usa-media-block__img" src="/libraries/nist-component-library/dist/img/icon-https.svg" role="img" alt="" aria-hidden="true">
<div class="usa-media-block__body">
<p>
<strong>Secure .gov websites use HTTPS</strong>
<br/>
A <strong>lock</strong> ( <span class="icon-lock">
<svg xmlns="http://www.w3.org/2000/svg" width="52" height="64" viewbox="0 0 52 64" class="usa-banner__lock-image" role="img" aria-labelledby="banner-lock-title banner-lock-description" focusable="false">
<title id="banner-lock-title">Lock</title>
<desc id="banner-lock-description">A locked padlock</desc><path fill="#000000" fill-rule="evenodd" d="M26 0c10.493 0 19 8.507 19 19v9h3a4 4 0 0 1 4 4v28a4 4 0 0 1-4 4H4a4 4 0 0 1-4-4V32a4 4 0 0 1 4-4h3v-9C7 8.507 15.507 0 26 0zm0 8c-5.979 0-10.843 4.77-10.996 10.712L15 19v9h22v-9c0-6.075-4.925-11-11-11z"/></svg>
</span>
) or <strong>https://</strong> means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
</p>
</div>
</div>
</div>
</div>
</div>
</section>
<!-- nist-index-ignore-end -->
<div data-elastic-exclude>
<!-- nist-index-ignore-start -->
<div class="nist-print-header" style="display:none;">
<p class="nist-print-header__url">https://www.nist.gov/blogs/taking-measure/taking-seat-periodic-table</p>
<img class="nist-print-header__logo" width="289" height="38" src="/libraries/nist-component-library/dist/img/logo/nist_logo_sidestack.svg" alt="National Institute of Standards and Technology" />
</div>
<div class="usa-overlay"></div>
<header class="usa-header nist-header--www nist-header--minimal" role="banner">
<div class="usa-navbar">
<div class="usa-logo flex-fill">
<a href="/" title="National Institute of Standards and Technology" aria-label="Home">
<img src="/libraries/nist-component-library/dist/img/logo/logo.svg" alt="National Institute of Standards and Technology" width="300px" height="80px" />
</a>
</div>
<div class="usa-header__right grid-row flex-auto">
<div class="grid-col-fill nist-header__search-group">
<form class="usa-search usa-search--small"
accept-charset="UTF-8"
action="/search"
id="search_form"
method="get">
<div role="search">
<label class="usa-sr-only" for="search-form">Search NIST</label>
<input class="usa-input" id="search-form" type="search" name="s" placeholder="Search NIST" required="" maxlength="128">
<button class="usa-button" type="submit"><img src="/libraries/nist-component-library/dist/img/usa-icons-bg/search--white.svg" class="usa-search__submit-icon" alt="Search"></button>
</div>
</form>
</div>
<div class="grid-col-auto padding-left-1">
<button class="usa-menu-btn">Menu</button>
</div>
</div>
</div>
<nav aria-label="Primary navigation" class="usa-nav">
<div class="usa-nav__inner">
<button class="usa-nav__close">Close</button>
<ul class="usa-nav__primary usa-accordion">
<li class="usa-nav__primary-item">
<a class="usa-nav__link" href="/publications">Publications</a>
</li>
<li class="usa-nav__primary-item">
<button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-2"><span>What We Do</span></button>
<div id="primary_menu-2" class="usa-nav__submenu usa-megamenu">
<div class="grid-row">
<div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
<li class="usa-nav__submenu-item">
<a href="/topics" class="usa-nav__link">All Topics</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/advanced-communications" class="usa-nav__link">Advanced communications</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/artificial-intelligence" class="usa-nav__link">Artificial intelligence</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/bioscience" class="usa-nav__link">Bioscience</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/buildings-construction" class="usa-nav__link">Buildings and construction</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/chemistry" class="usa-nav__link">Chemistry</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/cybersecurity" class="usa-nav__link">Cybersecurity</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/electronics" class="usa-nav__link">Electronics</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/energy" class="usa-nav__link">Energy</a>
</li>
</ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
<li class="usa-nav__submenu-item">
<a href="/environment" class="usa-nav__link">Environment</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/fire" class="usa-nav__link">Fire</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/forensic-science" class="usa-nav__link">Forensic science</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/health" class="usa-nav__link">Health</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/information-technology" class="usa-nav__link">Information technology</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/infrastructure" class="usa-nav__link">Infrastructure</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/manufacturing" class="usa-nav__link">Manufacturing</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/materials" class="usa-nav__link">Materials</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/mathematics-statistics" class="usa-nav__link">Mathematics and statistics</a>
</li>
</ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
<li class="usa-nav__submenu-item">
<a href="/metrology" class="usa-nav__link">Metrology</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/nanotechnology" class="usa-nav__link">Nanotechnology</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/neutron-research" class="usa-nav__link">Neutron research</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/performance-excellence" class="usa-nav__link">Performance excellence</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/physics" class="usa-nav__link">Physics</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/public-safety" class="usa-nav__link">Public safety</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/quantum-information-science" class="usa-nav__link">Quantum information science</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/resilience" class="usa-nav__link">Resilience</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/standards" class="usa-nav__link">Standards</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/transportation" class="usa-nav__link">Transportation</a>
</li>
</ul>
</div>
</div>
</div>
</li>
<li class="usa-nav__primary-item">
<button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-3"><span>Labs &amp; Major Programs</span></button>
<div id="primary_menu-3" class="usa-nav__submenu usa-megamenu">
<div class="grid-row">
<div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
<li class="usa-nav__submenu-item">
<a href="/adlp" class="usa-nav__link">Assoc Director of Laboratory Programs</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/laboratories" class="usa-nav__link">Laboratories</a>
<ul class="usa-nav__submenu-list">
<li>
<a href="/ctl" class="usa-nav__link">Communications Technology Laboratory</a>
</li>
<li>
<a href="/el" class="usa-nav__link">Engineering Laboratory</a>
</li>
<li>
<a href="/itl" class="usa-nav__link">Information Technology Laboratory</a>
</li>
<li>
<a href="/mml" class="usa-nav__link">Material Measurement Laboratory</a>
</li>
<li>
<a href="/pml" class="usa-nav__link">Physical Measurement Laboratory</a>
</li>
</ul>
</li>
</ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
<li class="usa-nav__submenu-item">
<a href="/user-facilities" class="usa-nav__link">User Facilities</a>
<ul class="usa-nav__submenu-list">
<li>
<a href="/ncnr" class="usa-nav__link">NIST Center for Neutron Research</a>
</li>
<li>
<a href="/cnst" class="usa-nav__link">CNST NanoFab</a>
</li>
</ul>
</li>
<li class="usa-nav__submenu-item">
<a href="/labs-major-programs/research-test-beds" class="usa-nav__link">Research Test Beds</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/laboratories/projects-programs" class="usa-nav__link">Research Projects</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/laboratories/tools-instruments" class="usa-nav__link">Tools &amp; Instruments</a>
</li>
</ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
<li class="usa-nav__submenu-item">
<a href="/major-programs" class="usa-nav__link">Major Programs</a>
<ul class="usa-nav__submenu-list">
<li>
<a href="/baldrige" class="usa-nav__link">Baldrige Performance Excellence Program</a>
</li>
<li>
<a href="/chips" class="usa-nav__link">CHIPS for America Initiative</a>
</li>
<li>
<a href="/mep" class="usa-nav__link">Manufacturing Extension Partnership (MEP)</a>
</li>
<li>
<a href="/oam" class="usa-nav__link">Office of Advanced Manufacturing</a>
</li>
<li>
<a href="/spo" class="usa-nav__link">Special Programs Office</a>
</li>
<li>
<a href="/tpo" class="usa-nav__link">Technology Partnerships Office</a>
</li>
</ul>
</li>
</ul>
</div>
</div>
</div>
</li>
<li class="usa-nav__primary-item">
<button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-4"><span>Services &amp; Resources</span></button>
<div id="primary_menu-4" class="usa-nav__submenu usa-megamenu">
<div class="grid-row">
<div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
<li class="usa-nav__submenu-item">
<a href="/content/standards-measurements" class="usa-nav__link">Standards and Measurements</a>
<ul class="usa-nav__submenu-list">
<li>
<a href="/calibrations" class="usa-nav__link">Calibration Services</a>
</li>
<li>
<a href="/nvlap" class="usa-nav__link">Laboratory Accreditation (NVLAP)</a>
</li>
<li>
<a href="/nist-quality-system" class="usa-nav__link">Quality System</a>
</li>
<li>
<a href="/srm" class="usa-nav__link">Standard Reference Materials (SRMs)</a>
</li>
<li>
<a href="/sri" class="usa-nav__link">Standard Reference Instruments (SRIs)</a>
</li>
<li>
<a href="/standardsgov" class="usa-nav__link">Standards.gov</a>
</li>
<li>
<a href="/pml/time-and-frequency-division/time-services" class="usa-nav__link">Time Services</a>
</li>
<li>
<a href="/pml/owm" class="usa-nav__link">Office of Weights and Measures</a>
</li>
</ul>
</li>
</ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
<li class="usa-nav__submenu-item">
<a href="/services-resources/software" class="usa-nav__link">Software</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/data" class="usa-nav__link">Data</a>
<ul class="usa-nav__submenu-list">
<li>
<a href="https://webbook.nist.gov/chemistry/" class="usa-nav__link">Chemistry WebBook</a>
</li>
<li>
<a href="https://nvd.nist.gov/" class="usa-nav__link">National Vulnerability Database</a>
</li>
<li>
<a href="/pml/productsservices/physical-reference-data" class="usa-nav__link">Physical Reference Data</a>
</li>
<li>
<a href="/srd" class="usa-nav__link">Standard Reference Data (SRD)</a>
</li>
</ul>
</li>
<li class="usa-nav__submenu-item">
<a href="https://shop.nist.gov/" class="usa-nav__link">Storefront</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/tpo" class="usa-nav__link">License &amp; Patents</a>
</li>
</ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
<li class="usa-nav__submenu-item">
<a href="https://csrc.nist.gov/" class="usa-nav__link">Computer Security Resource Center (CSRC)</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/nist-research-library" class="usa-nav__link">NIST Research Library</a>
</li>
</ul>
</div>
</div>
</div>
</li>
<li class="usa-nav__primary-item">
<button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-5"><span>News &amp; Events</span></button>
<div id="primary_menu-5" class="usa-nav__submenu usa-megamenu">
<div class="grid-row">
<div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
<li class="usa-nav__submenu-item">
<a href="/news-events/news" class="usa-nav__link">News</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/news-events/events" class="usa-nav__link">Events</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/blogs" class="usa-nav__link">Blogs</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/feature-stories" class="usa-nav__link">Feature Stories</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/awards" class="usa-nav__link">Awards</a>
</li>
</ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
<li class="usa-nav__submenu-item">
<a href="/video-gallery" class="usa-nav__link">Video Gallery</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/image-gallery" class="usa-nav__link">Image Gallery</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/pao/media-contacts" class="usa-nav__link">Media Contacts</a>
</li>
</ul>
</div>
</div>
</div>
</li>
<li class="usa-nav__primary-item">
<button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-6"><span>About NIST</span></button>
<div id="primary_menu-6" class="usa-nav__submenu usa-megamenu">
<div class="grid-row">
<div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
<li class="usa-nav__submenu-item">
<a href="/about-nist" class="usa-nav__link">About Us</a>
<ul class="usa-nav__submenu-list">
<li>
<a href="/director/leadership" class="usa-nav__link">Leadership</a>
</li>
<li>
<a href="/director/nist-organization-structure" class="usa-nav__link">Organization Structure</a>
</li>
<li>
<a href="/about-nist/budget-planning" class="usa-nav__link">Budget &amp; Planning</a>
</li>
</ul>
</li>
<li class="usa-nav__submenu-item">
<a href="/about-nist/contact-us" class="usa-nav__link">Contact Us</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/about-nist/visit" class="usa-nav__link">Visit</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/careers" class="usa-nav__link">Careers</a>
<ul class="usa-nav__submenu-list">
<li>
<a href="/iaao/academic-affairs-office" class="usa-nav__link">Student programs</a>
</li>
</ul>
</li>
</ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
<li class="usa-nav__submenu-item">
<a href="/about-nist/work-nist" class="usa-nav__link">Work with NIST</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/history" class="usa-nav__link">History</a>
<ul class="usa-nav__submenu-list">
<li>
<a href="http://nistdigitalarchives.contentdm.oclc.org/" class="usa-nav__link">NIST Digital Archives</a>
</li>
<li>
<a href="/nist-museum" class="usa-nav__link">NIST Museum</a>
</li>
<li>
<a href="/nist-and-nobel" class="usa-nav__link">NIST and the Nobel</a>
</li>
</ul>
</li>
<li class="usa-nav__submenu-item">
<a href="/education" class="usa-nav__link">Educational Resources</a>
</li>
</ul>
</div>
</div>
</div>
</li>
</ul>
</div>
</nav>
</header>
<!-- nist-index-ignore-end -->
</div>
<div class="grid-container">
</div>
<div
id="block-nist-www-content" class="nist-block"
>
<section
class="nist-page__content usa-section clearfix"
>
<a id="main-content" tabindex="-1"></a>
<div
class="nist-page__region nist-page__region--content-top-full"
>
<div
class="nist-block"
>
<div class="entity-reference">
<div class="nist-blog-header nist-blog-header--purple nist-blog-header--inner">
<div class="nist-blog-header__bkgrd">
<div class="nist-blog-header__main grid-container">
<div class="grid-row">
<h2 class="nist-blog-header__title">
<a href="/blogs/taking-measure"> Taking Measure
</a>
</h2>
<div class="nist-blog-header__tagline">
<p class="text">Just a Standard Blog</p>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
<div class="grid-container margin-top-4">
<div
class="nist-page__region nist-page__region--content-top"
>
<div
class="nist-block"
>
<h1 class="nist-page__title">Taking a Seat at the Periodic Table</h1>
</div>
<div
class="font-body-md"
>
<div class="daterange"><time datetime="2017-02-07T12:00:00Z">February 7, 2017</time>
</div>
</div>
<div
class="nist-block"
>
<span>By: </span>
<a href="/blogs/taking-measure/authors/michael-e-newman" hreflang="en">Michael E. Newman</a>
</div>
<div
class="nist-block"
>
<!-- nist-index-ignore-start -->
<div data-elastic-exclude class="nist-block nist-social__wrapper">
<h2 class="nist-social__title">Share</h2>
<div class="social-media-sharing">
<div class="nist-social__wrapper--share">
<div>
<a target="_blank" rel="noopener" href="https://www.facebook.com/share.php?u=https://www.nist.gov/blogs/taking-measure/taking-seat-periodic-table"
title="Facebook" class="nist-social nist-social--facebook-gray">
<span>Facebook</span>
</a>
</div>
<div>
<a target="_blank" rel="noopener" href="https://www.linkedin.com/shareArticle?mini=true&amp;url=https://www.nist.gov/blogs/taking-measure/taking-seat-periodic-table&amp;source=https://www.nist.gov/blogs/taking-measure/taking-seat-periodic-table"
title="Linkedin" class="nist-social nist-social--linkedin-gray">
<span>Linkedin</span>
</a>
</div>
<div>
<a target="_blank" rel="noopener" href="https://x.com/intent/tweet?url=https://www.nist.gov/blogs/taking-measure/taking-seat-periodic-table&amp;status=https://www.nist.gov/blogs/taking-measure/taking-seat-periodic-table"
title="X.com" class="nist-social nist-social--x-gray">
<span>X.com</span>
</a>
</div>
<div>
<a href="mailto:?subject=NIST.gov&amp;body=Check out this site https://www.nist.gov/blogs/taking-measure/taking-seat-periodic-table"
title="Email" class="nist-social nist-social--envelope-gray">
<span>Email</span>
</a>
</div>
</div>
</div>
</div>
<!-- nist-index-ignore-end -->
</div>
</div>
</div>
<div class="grid-container margin-top-4">
<div class="grid-row grid-gap-6">
<div
class="nist-page__region nist-page__region--content tablet-lg:grid-col-8"
>
<div
class="nist-block"
>
<div class="text-with-summary">
<figure class="nist-image--lightbox nist-image" data-lightbox="https://www.nist.gov/sites/default/files/styles/2800_x_2800_limit/public/images/2017/11/08/Element-117.jpg?itok=LY7g4LyO" data-media-id="381051">
<img loading="lazy" src="/sites/default/files/styles/960_x_960_limit/public/images/2017/11/08/Element-117.jpg?itok=KZnrGNla" width="960" height="540" alt="Roundish shape clear ball containing multiple round-ish shapes with red or orange centers" title="Tennessine" typeof="foaf:Image" />
<figcaption class="nist-image__caption">
<div data-caption-editable="true" class="nist-image__caption-content">
<p>Artist's rendition of element 117, tennessine.</p>
</div>
<div class="nist-image__credit">
<span class="nist-image__credit-label">Credit:</span>
Kwei-Yu Chu/Lawrence Livermore National Laboratory
</div>
</figcaption>
</figure>
<p>In case you haven’t already heard, if you wanted to give your loved one that special, once-in-a-lifetime gift by naming one of the elements in row 7 of the Periodic Table after him or her, it’s too late (and probably against the rules anyway, but more on that later). With the <a href="https://iupac.org/iupac-announces-the-names-of-the-elements-113-115-117-and-118/">recently announced</a> official names for elements with atomic numbers 113 (<a href="https://en.wikipedia.org/wiki/Nihonium">nihonium</a>), 115 (<a href="https://en.wikipedia.org/wiki/Moscovium">moscovium</a>), 117 (<a href="https://en.wikipedia.org/wiki/Tennessine">tennessine</a>) and 118 (<a href="https://en.wikipedia.org/wiki/Oganesson">oganesson</a>), the all-radioactive row 7 of the Periodic Table is now complete. Included are two (thorium and uranium) found naturally, five that result from the radioactive decay of other elements—such as everyone’s favorite cinematic time machine fuel, <a href="https://en.wikipedia.org/wiki/Plutonium">plutonium</a>—and 25 that can only be synthesized in the laboratory.</p>
<p>The good news for those who would like a shot at naming an element is that there still may be a few seats left at the Periodic Table. Scientists are already hard at work, with <a href="https://www.chemistryworld.com/news/beyond-element-118-the-next-row-of-the-periodic-table/9400.article">some predicting</a> that we will reach element 124 within a generation. In fact, famed physicist <a href="https://en.wikipedia.org/wiki/Richard_Feynman">Richard Feynman</a> once surmised that the limit might go as high as element 137.</p>
<p>My interest in “elemental nomenclature” is purely one of curiosity. I have always been fascinated by etymology, the study of word, phrase and name origins, so when I heard that the final four row 7 elements had been officially named, it spurred me to learn more about the naming process.</p>
<h2>Call Me … Nihonium</h2>
<p>What are the requirements for naming an element? First, of course, you need to discover a new one—and since every new element since 1937 has been artificially created, all that takes is patience, time, a heap of luck, and oh yes, a little something known as a particle accelerator. Once you have yours up and running, just smash together atoms of two elements and hope their nuclei fuse into a new element long enough for the proton total to be counted. For example, scientists in 2004 first synthesized nihonium (from the Japanese word “<em>nihon</em>,” which is what most Japanese call Japan, the place where the element was discovered), possessing 113 protons, by fusing <a href="https://en.wikipedia.org/wiki/Zinc">zinc</a> atoms, containing 30 protons each, with <a href="https://en.wikipedia.org/wiki/Bismuth">bismuth</a> atoms, containing 83 protons each.</p>
<figure class=" align-center nist-image--lightbox nist-image" role="group">
<div data-lightbox="https://www.nist.gov/sites/default/files/styles/2800_x_2800_limit/public/images/2017/08/15/RichardFeynman-PaineMansionWoods1984_copyrightTamikoThiel_bw.jpg?itok=dLyA1wd8" data-media-id="381061">
<img alt="BW photo of Richard Feynman standing in the Paine Mansion Woods in 1984" height="541" loading="lazy" src="/sites/default/files/images/2017/08/15/RichardFeynman-PaineMansionWoods1984_copyrightTamikoThiel_bw.jpg" typeof="foaf:Image" width="470">
</div>
<figcaption class="nist-image__caption">Famed physicist Richard Feynman predicted that there could be as many as 137 elements, and he wasn't joking … this time.<div class="nist-image__credit">
<span class="nist-image__credit-label">Credit:</span>
Tamiko Thiel
</div></figcaption>
</figure>
<p>The harder part may be convincing the <a href="https://iupac.org/">International Union of Pure and Applied Chemistry</a> (IUPAC), custodian of the Periodic Table, that you actually did it. Until the existence of a new element is verified, IUPAC assigns it a “placeholder” name using Latin digits that correspond to the candidate’s atomic number. In the case of nihonium, it was known during the 12 years between its discovery and official recognition as ununtrium— “un” for one, “un” for one and “tri” for three—or 113.</p>
<p>Using the same specifications, the element that should have an atomic number of 119 is currently tagged with “ununennium.” (Try saying that five times fast.) Researchers in Germany, Russia and the United States have been bombarding the heck out of atoms since 1985 but haven’t yet hit the 119-proton jackpot.</p>
<h2>Who or Where or What’s in a Name?</h2>
<p>For the sake of argument, let’s say that you managed to create element 119 using your backyard accelerator. First, congratulations! As discoverer, you will be invited by IUPAC’s Inorganic Chemistry Division to propose a name and symbol for consideration. But hold on there, Einstein, you can’t name your element anything you want … you have to follow the rules, and the rules say that elements can only be named after:</p>
<ul>
<li>A mythological concept or character, including an astronomical object (No, Yoda from <em>Star Wars </em>does not count as a mythological character);</li>
<li>A mineral, or similar substance;</li>
<li>A place, or geographical region (Although I’m pretty sure that “tuscaloosium” isn’t going to fly no matter how big a Crimson Tide fan you are);</li>
<li>A property of the new element; or</li>
<li>A scientist (So, sorry rock and rollers, the Periodic Table will never feature a “mccartneyum” or “springsteenium”).</li>
</ul>
<p>So, unless your loved one’s name conforms to these rules, you’re out of luck. And “<a href="https://en.wikipedia.org/wiki/Einsteinium">Einstein</a>” is already taken.</p>
<p>The 118 elements for which we have names got them from 17 different languages, with Greek (47) and Latin (26) leading the pack. Among the more unusual languages represented: Scottish Gaelic for <a href="https://en.wikipedia.org/wiki/Strontium">strontium</a>, named after Strontian, a village in Scotland near where the mineral was discovered in 1790; and Old Norse being responsible for two names, <a href="https://en.wikipedia.org/wiki/Thorium">thorium</a> and <a href="https://en.wikipedia.org/wiki/Vanadium">vanadium</a>, taken from Norse gods Thor and Vanadis. &nbsp;Eight cities have been the inspiration for element names but one, the tiny island village of Ytterby, Sweden, tops them all. This hamlet of fewer than 2,000 residents is the location of a now-defunct mine that yielded seven different elements, four of which take their names directly from the town: <a href="https://en.wikipedia.org/wiki/Erbium">erbium</a>, <a href="https://en.wikipedia.org/wiki/Terbium">terbium</a>, <a href="https://en.wikipedia.org/wiki/Ytterbium">ytterbium</a> and <a href="https://en.wikipedia.org/wiki/Yttrium">yttrium</a>. The other three are <a href="https://en.wikipedia.org/wiki/Holmium">holmium</a>, derived from the Swedish capital, Stockholm; <a href="https://en.wikipedia.org/wiki/Thulium">thulium</a>, named after Thule, a mythic analog of Scandinavia; and <a href="https://en.wikipedia.org/wiki/Gadolinium">gadolinium</a>, honoring the Finnish chemist <a href="https://en.wikipedia.org/wiki/Johan_Gadolin">Johan Gadolin</a> who discovered yttrium in an ore sample from the mine. In 1989, <a href="https://www.astm.org/">ASTM International</a> installed a plaque at the former entrance to the mine, commemorating the site as a historical landmark.</p>
<p>Sixteen scientists have had their surnames adapted for 15 elements in the Periodic Table (<a href="https://en.wikipedia.org/wiki/Curium">curium</a> is named after both Pierre and <a href="https://en.wikipedia.org/wiki/Marie_Curie">Marie Curie</a>) but two others are remembered for <em>almost </em>receiving chemistry’s foremost tribute. Soviet scientists lobbied in 1966 for element 104 to be called kurchatovium after physicist <a href="https://en.wikipedia.org/wiki/Igor_Kurchatov">Igor Kurchatov</a>, father of the Soviet atomic bomb. Researchers in the United States protested and suggested three years later that the element instead be named rutherfordium for Lord Ernest Rutherford, the Nobelist who discovered the atomic nucleus. More controversy ensued in 1970 when researchers at the University of California, Berkeley, requested that element 105—for which they claimed discovery—be named hahnium to honor German chemist and Nobel Prize winner Otto Hahn. Concurrently, a Soviet team—that believed it was 105’s rightful finders—suggested nielsbohrium in honor of the Danish nuclear physicist <a href="https://en.wikipedia.org/wiki/Niels_Bohr">Niels Bohr</a>, pioneer of the atomic structure theory.</p>
<p>The East-West debate over these names became known as the <a href="https://en.wikipedia.org/wiki/Transfermium_Wars">Transfermium Wars</a>—a pithy nod to the fact that it involved elements with atomic numbers higher than <a href="https://en.wikipedia.org/wiki/Fermium">fermium</a>. It took until 1997 before IUPAC could resolve the issue, giving the Americans one win by selecting <a href="https://en.wikipedia.org/wiki/Rutherfordium">rutherfordium</a> for element 104, and the Russians the other by tabbing element 105 as <a href="https://en.wikipedia.org/wiki/Dubnium">dubnium</a> after the city of Dubna, home of the <a href="http://www.jinr.ru/main-en/">Joint Institute for Nuclear Research</a>. Bohr got his element when number 107 was named <a href="https://en.wikipedia.org/wiki/Bohrium">bohrium</a> at the same time.</p>
<p>Unfortunately for both Hahn and Kurchatov, they will never get seats at the Periodic Table. IUPAC rules state that any name previously used for an element, even if it is eventually replaced by another, cannot be used again.</p>
<h2>Back in our Element</h2>
<p>Finally, while my agency, the National Institute of Standards and Technology (NIST), has yet to be recognized with a&nbsp;“nistium” or “gaithersburgium” (we’re headquartered in Gaithersburg, Maryland), its 116-year history does include many connections to members of the Periodic Table. Some examples:</p>
<ul>
<li>The frequency of microwave radiation from element 55, <a href="https://en.wikipedia.org/wiki/Caesium">cesium</a>, has been used by NIST and others around the world to define the second and drive atomic clocks like the current U.S. time and frequency standard, <a data-entity-substitution="canonical" data-entity-type="node" data-entity-uuid="96f9b944-2096-47cd-b87f-e2739001847e" href="/news-events/news/2014/04/nist-launches-new-us-time-standard-nist-f2-atomic-clock" title="NIST Launches a New U.S. Time Standard: NIST-F2 Atomic Clock">NIST-F2</a>.</li>
</ul>
<ul>
<li>Atoms of element 37, <a href="https://en.wikipedia.org/wiki/Rubidium">rubidium</a>, were the foundation for creating a <a href="https://www.nist.gov/news-events/news/2001/10/bose-einstein-condensate-new-form-matter">Bose-Einstein condensate</a>, a fourth state of matter first observed in 1995 at <a href="https://jila.colorado.edu/">JILA</a>, a joint institute of NIST and the University of Colorado at Boulder.</li>
</ul>
<ul>
<li>In 1931, NIST scientists produced America’s first quantity of liquefied element 2, <a href="https://en.wikipedia.org/wiki/Helium">helium</a>—the ultracold coolant now used in magnetic resonance imaging machines, or MRIs.</li>
</ul>
<ul>
<li>A cylinder made from two “next-door neighbor” elements number 77, <a href="https://en.wikipedia.org/wiki/Iridium">iridium</a>, and number 78, <a href="https://en.wikipedia.org/wiki/Platinum">platinum</a>, that is stored in a vault on NIST’s Maryland campus, is the official U.S. standard for the <a href="https://www.nist.gov/pml/weights-and-measures/si-units-mass">kilogram</a>. (At least, that is, until 2018, when the <a href="http://www.bipm.org/en/about-us/">International Bureau of Weights and Measures</a> is scheduled to <a href="https://www.nist.gov/pml/productsservices/redefining-kilogram">redefine the kilogram</a> as a fundamental constant of nature … but I digress.)</li>
</ul>
<p>To honor the world’s 118 elements, including the four-newest, NIST created its own colorful, informative and, of course, accurate to the agency’s rigorous standards, version of the <a href="https://www.nist.gov/pml/periodic-table-elements">Periodic Table</a>. Download yours today!</p>
</div>
</div>
<div
class="nist-block"
>
<div class="nist-tags">
<a href="/blogs/taking-measure/categories/248416">Chemistry</a> and
<a href="/blogs/taking-measure/categories/249241">Physics</a></div>
</div>
<div
class="nist-block"
>
<h2
class="nist-block__title"
>About the author</h2>
<div class="nist-field nist-field--label-hidden entity-reference">
<div class="nist-field__items">
<div class="nist-field__item">
<article
about="/blogs/taking-measure/authors/michael-e-newman" class="nist-teaser"
>
<div class="nist-teaser__image">
<div class="entity-reference"> <a href="/blogs/taking-measure/authors/michael-e-newman" hreflang="en"><img loading="lazy" src="/sites/default/files/styles/thumbnail/public/images/2017/03/08/michael_newman_in_nist_office.jpg?itok=BUvLLwwE" width="100" height="80" alt="Michael E. Newman" typeof="foaf:Image" />
</a>
</div>
</div>
<div class="nist-teaser__content-wrapper">
<header>
<h3 class="nist-teaser__title"><a href="/blogs/taking-measure/authors/michael-e-newman"><span>Michael E. Newman</span>
</a></h3>
</header>
<div class="nist-teaser__content">
<div class="text-with-summary"><p>Trivia lover and spare-time etymologist Michael E. Newman has been at NIST for 25 years and currently serves as a senior communications officer. A native of Houston, he originally planned a career as a research scientist but detoured into science communications after his first (and only) year of graduate school. His public affairs, journalistic and AV experiences prior to NIST include time as a reporter for the Houston Chronicle, a medical TV writer/producer for the University of Texas Health Science Center at Houston, a features reporter at an NPR affiliate, an ABC-TV news producer, an audiovisual production manager and media spokesman for a Fortune 500 oil and gas company, and a public affairs specialist for the National Cancer Institute.</p></div>
</div>
</div>
</article>
</div>
</div>
</div>
</div>
<div
class="views-element-container nist-block no-print"
>
<h2
class="nist-block__title"
>Related posts</h2>
<div><div class="js-view-dom-id-3f97254c482b0062dcd63e153221229d63078ee5f72da47854d6985ab1144131">
<div>
<article
about="/blogs/taking-measure/high-flying-science-how-and-why-we-sent-refrigerator-halfway-space" class="nist-teaser"
>
<div class="nist-teaser__image">
<div class="entity-reference"> <a href="/blogs/taking-measure/high-flying-science-how-and-why-we-sent-refrigerator-halfway-space" hreflang="en"><img loading="lazy" src="/sites/default/files/styles/thumbnail/public/images/2025/01/23/ephraim_gau_tes_balloon_in_air_012125.JPG?itok=vkGGerAo" width="75" height="100" alt="A rectangular box coated with reflective foil hangs from cables over a parking lot." typeof="foaf:Image" />
</a>
</div>
</div>
<div class="nist-teaser__content-wrapper">
<header>
<h3 class="nist-teaser__title"><a href="/blogs/taking-measure/high-flying-science-how-and-why-we-sent-refrigerator-halfway-space"><span>High-Flying Science: How and Why We Sent a Refrigerator Halfway to Space</span>
</a></h3>
<div class="nist-teaser__date">
<div class="daterange"><time datetime="2025-02-12T12:00:00Z">February 12, 2025</time>
</div>
</div>
</header>
<div class="nist-teaser__content">
<div class="text-with-summary"> NIST-developed tools can study the remnants of the Big Bang and more, and now researchers are working to launch these tools high above the Earth’s atmosphere —
</div>
</div>
</div>
</article>
</div>
<div>
<article
about="/blogs/taking-measure/5-concepts-can-help-you-understand-quantum-mechanics-and-technology-without" class="nist-teaser"
>
<div class="nist-teaser__image">
<div class="entity-reference"> <a href="/blogs/taking-measure/5-concepts-can-help-you-understand-quantum-mechanics-and-technology-without" hreflang="en"><img loading="lazy" src="/sites/default/files/styles/thumbnail/public/images/2023/10/16/tara_fortier_working_in_lab_october_2023.jpg?itok=RkM9HePP" width="100" height="67" alt="A researcher wearing safety glasses reaches into a box of circuitry and other equipment, which emits a green glow. " typeof="foaf:Image" />
</a>
</div>
</div>
<div class="nist-teaser__content-wrapper">
<header>
<h3 class="nist-teaser__title"><a href="/blogs/taking-measure/5-concepts-can-help-you-understand-quantum-mechanics-and-technology-without"><span>5 Concepts Can Help You Understand Quantum Mechanics and Technology — Without Math!</span>
</a></h3>
<div class="nist-teaser__date">
<div class="daterange"><time datetime="2025-02-05T12:00:00Z">February 5, 2025</time>
</div>
</div>
</header>
<div class="nist-teaser__content">
<div class="text-with-summary"> Quantum is everywhere, and you can understand the basic quirks of life at the quantum level … no math required.
</div>
</div>
</div>
</article>
</div>
<div>
<article
about="/blogs/taking-measure/robots-and-ai-are-working-together-bring-you-better-medicines-shampoo-and-more" class="nist-teaser"
>
<div class="nist-teaser__image">
<div class="entity-reference"> <a href="/blogs/taking-measure/robots-and-ai-are-working-together-bring-you-better-medicines-shampoo-and-more" hreflang="en"><img loading="lazy" src="/sites/default/files/styles/thumbnail/public/images/2024/12/18/peter_beaucage_afl_equipment_121024.jpg?itok=CdxapNjs" width="100" height="67" alt="Peter Beaucage wears safety glasses as he stands in the lab, holding a piece of equipment on display. " typeof="foaf:Image" />
</a>
</div>
</div>
<div class="nist-teaser__content-wrapper">
<header>
<h3 class="nist-teaser__title"><a href="/blogs/taking-measure/robots-and-ai-are-working-together-bring-you-better-medicines-shampoo-and-more"><span>Robots and AI Are Working Together to Bring You Better Medicines, Shampoo and More</span>
</a></h3>
<div class="nist-teaser__date">
<div class="daterange"><time datetime="2025-01-15T12:00:00Z">January 15, 2025</time>
</div>
</div>
</header>
<div class="nist-teaser__content">
<div class="text-with-summary"> Products you use every day are carefully formulated in a lab. Experts at NIST are now working to revolutionize how those products are made.
</div>
</div>
</div>
</article>
</div>
</div>
</div>
</div>
<div
class="nist-block no-print"
>
<h2
class="nist-block__title"
>Comments</h2>
<section>
<h2>Add new comment</h2>
<link rel="stylesheet" media="all" href="/sites/default/files/css/css_Lx5yvw0vUi4TN7C0L-5Rdrp4Q049mXEKn-dXREWOtBs.css?delta=0&amp;language=en&amp;theme=nist_www&amp;include=eJxLzCvJTMov0U-E0Hpp-UW5OsmJBSXJGYn6SYnFqTppmTklqUX6KUWlBYk5ehAeAD47FNs&amp;exclude=eJx1UAGOwyAM-xAdT0IBsi5bIBXQ9nqvv9B2WjXpJISwE-zEHsLLNdEzWf95u2c1_p8SBclmFBkZHWTgrVGo9pswmWpzd1IuyppZILpWVIbyaEc4ypUaUpqKLGi_iT7CzrUHJlRnYQ_FJYk2UgWvwkz5ZepWGyadsOLeb0cWD3x9D6eUfSBELG_o1nW9dl9wb8Gf1g1sLPMEfDuhCZIS5vamTzj4bVgIVyyHU4Ix052CWSiiOEweo6aBHC3D7zb0PIym07DYAFMjzbRKIGCXMBL0ffQ3wyZzc7pw0EjKZiVjEDbdqtr9vmkiM-NBueecJlXI81EcOh46_myYKBTpQf8BO5rHtg" />
<form class="comment-comment-node-blog-form comment-form usa-form antibot" novalidate="novalidate" data-drupal-selector="comment-form" data-action="/comment/reply/node/1246736/comment_node_blog" action="/antibot" method="post" id="comment-form" accept-charset="UTF-8">
<noscript>
<div class="antibot-no-js antibot-message antibot-message-warning">You must have JavaScript enabled to use this form.</div>
</noscript>
<div class="form-item js-form-item form-type-textfield js-form-type-textfield form-item-name js-form-item-name">
<label for="edit-name" class="usa-label">
Your name
</label>
<input data-drupal-default-value="Anonymous" data-drupal-selector="edit-name" type="text" id="edit-name" name="name" value="" size="30" maxlength="60" class="form-text usa-input" />
</div>
<input data-drupal-selector="form-d4n6y8hxatpr1yjkyxotx-sqcbqjz5lg6xd18y5fq9e" type="hidden" name="form_build_id" value="form-d4N6y8HXATPr1YJKyxotx_sQCbqjz5Lg6XD18y5FQ9E" class="usa-input" /><input data-drupal-selector="edit-comment-comment-node-blog-form" type="hidden" name="form_id" value="comment_comment_node_blog_form" class="usa-input" /><input data-drupal-selector="edit-antibot-key" type="hidden" name="antibot_key" value="" class="usa-input" /><div class="field--type-text-long field--name-comment-body field--widget-text-textarea js-form-wrapper form-wrapper" data-drupal-selector="edit-comment-body-wrapper" id="edit-comment-body-wrapper"> <div class="js-text-format-wrapper js-form-item form-item">
<div class="form-item js-form-item form-type-textarea js-form-type-textarea form-item-comment-body-0-value js-form-item-comment-body-0-value">
<label for="edit-comment-body-0-value" class="usa-label form-required">
Comment
<span class="usa-label--required"> <span class="usa-sr-only">Required</span>*</span></label>
<div class="form-textarea-wrapper">
<textarea class="js-text-full text-full form-textarea required usa-textarea resize-vertical" data-entity_embed-host-entity-langcode="en" data-media-embed-host-entity-langcode="en" data-drupal-selector="edit-comment-body-0-value" id="edit-comment-body-0-value" name="comment_body[0][value]" rows="5" cols="60" placeholder="" required="required" aria-required="true"></textarea>
</div>
</div>
<div class="js-filter-wrapper filter-wrapper hidden js-form-wrapper form-wrapper" data-drupal-selector="edit-comment-body-0-format" id="edit-comment-body-0-format"><div class="js-filter-guidelines filter-guidelines js-form-wrapper form-wrapper" data-drupal-selector="edit-comment-body-0-format-guidelines" id="edit-comment-body-0-format-guidelines"><div data-drupal-format-id="plain_text">
<h4>Plain text</h4>
<ul>
<li>No HTML tags allowed.</li>
<li>Web page addresses and email addresses turn into links automatically.</li>
<li>Lines and paragraphs break automatically.</li>
</ul>
</div>
</div>
</div>
</div>
</div>
<fieldset data-drupal-selector="edit-captcha" class="captcha captcha-type-challenge--image">
<legend class="captcha__title js-form-required form-required">
CAPTCHA
</legend>
<div class="captcha__element">
<input data-drupal-selector="edit-captcha-sid" type="hidden" name="captcha_sid" value="652304171" class="usa-input" /><input data-drupal-selector="edit-captcha-token" type="hidden" name="captcha_token" value="dA7O2q8PJUgSHeXBbAowUD8GWqqSt8-828V1JCC0gts" class="usa-input" /><div class="captcha__image-wrapper js-form-wrapper form-wrapper" data-drupal-selector="edit-captcha-image-wrapper" id="edit-captcha-image-wrapper"><img data-drupal-selector="edit-captcha-image" src="/image-captcha-generate/652304171/1741100887" width="180" height="60" alt="Image CAPTCHA" title="Image CAPTCHA" loading="lazy" typeof="foaf:Image" />
</div>
<div class="form-item js-form-item form-type-textfield js-form-type-textfield form-item-captcha-response js-form-item-captcha-response">
<label for="edit-captcha-response" class="usa-label form-required">
What code is in the image?
<span class="usa-label--required"> <span class="usa-sr-only">Required</span>*</span></label>
<input autocomplete="off" data-drupal-selector="edit-captcha-response" aria-describedby="edit-captcha-response--description" type="text" id="edit-captcha-response" name="captcha_response" value="" size="15" maxlength="128" class="form-text required usa-input" required="required" aria-required="true" />
<div id="edit-captcha-response--description" class="description help-block">
Enter the characters shown in the image.
</div>
</div>
</div>
<div class="captcha__description description">This question is for testing whether or not you are a human visitor and to prevent automated spam submissions.</div>
</fieldset>
<div data-drupal-selector="edit-actions" class="form-actions js-form-wrapper form-wrapper" id="edit-actions--2"><input data-drupal-selector="edit-submit" type="submit" id="edit-submit" name="op" value="Save" class="button button--primary js-form-submit form-submit usa-button" /></div>
<div class="comments__disclaimer padding-top-2">
<em>Please be respectful when posting comments. We will post all comments without editing as long as they are appropriate for a public, family friendly website, are on topic and do not contain profanity, personal attacks, misleading or false information/accusations or promote specific commercial products, services or organizations. Comments that violate our comment policy or include links to non-government organizations/web pages will not be posted.</em>
</div>
</form>
</section>
</div>
</div>
<aside class="nist-page__region nist-page__region--sidebar-second tablet-lg:grid-col-4">
<div>
<div
class="nist-block"
>
<div>
<div about="/blogs/taking-measure">
<div
class="nist-block no-print"
>
<h2
class="nist-block__title"
>Our Science in Your Inbox</h2>
<div class="text-long"><p>Subscribe to our weekly emails.</p>
<form action="https://public.govdelivery.com/accounts/USNIST/subscribers/qualify" accept-charset="UTF-8" method="post">
<input name="utf8" type="hidden" value="&#x2713;">
<input type="hidden" name="authenticity_token" value="GleKn0r3EFkuIRsIWsyLN6Mrqim4qc3U7eIUCWGqBFz2ziQ/qv0gnQTJUhVbKHMSlmrsC7UHIm6S8IfK6qk9EQ==">
<input type="hidden" name="topic_id" id="topic_id" value="USNIST_309">
<div class="grid-row grid-gap-1">
<div class="tablet:grid-col-8">
<label class="usa-sr-only" for="email">Enter Email Address</label>
<input class="usa-input" type="text" name="email" id="email" title="email" placeholder="Your Email Address">
</div>
<div class="tablet:grid-col-4">
<input type="submit" name="commit" value="Sign Up" class="usa-button margin-top-1">
</div>
</div>
</form>
</div>
</div>
<div
class="views-exposed-form usa-form filters nist-block" novalidate="novalidate" data-drupal-selector="views-exposed-form-search-blog-taking-measure-search-page"
>
<h2
class="nist-block__title"
>Search</h2>
<form action="/blogs/taking-measure/search" method="get" id="views-exposed-form-search-blog-taking-measure-search-page" accept-charset="UTF-8" class="usa-form">
<div class="form-item js-form-item form-type-textfield js-form-type-textfield form-item-k js-form-item-k form-no-label">
<input placeholder="Search this blog" data-drupal-selector="edit-k" type="text" id="edit-k" name="k" value="" size="30" maxlength="128" class="form-text usa-input" />
<div id="edit-k--description" class="description help-block">
Put exact phrase in quotes (e.g., "artificial intelligence")
</div>
</div>
<div class="grid-col-12 form-actions js-form-wrapper form-wrapper" data-drupal-selector="edit-actions" id="edit-actions"><input data-drupal-selector="edit-submit-search-blog" type="submit" id="edit-submit-search-blog" value="Search" class="button js-form-submit form-submit usa-button" /></div>
</form>
</div>
<div
class="nist-block no-print"
>
<h2
class="nist-block__title"
>Stay connected</h2>
<div><a href="https://www.facebook.com/nist" class="nist-social nist-social--facebook" title="Facebook" ><span>Facebook</span></a><a href="https://www.linkedin.com/company/nist" class="nist-social nist-social--linkedin" title="LinkedIn" ><span>LinkedIn</span></a><a href="https://www.x.com/nist" class="nist-social nist-social--x" title="X (Twitter)" ><span>X (Twitter)</span></a><a href="https://www.youtube.com/nist" class="nist-social nist-social--youtube" title="Youtube" ><span>Youtube</span></a><a href="https://www.instagram.com/nist/" class="nist-social nist-social--instagram" title="Instagram" ><span>Instagram</span></a><a href="https://public.govdelivery.com/accounts/USNIST/subscriber/new?topic_id=USNIST_309" class="nist-social nist-social--envelope" title="GovDelivery" ><span>GovDelivery</span></a></div>
</div>
<div
class="views-element-container nist-block"
>
<h2
class="nist-block__title"
>Categories</h2>
<div><div class="js-view-dom-id-34f3c84560aa3c55a2b99fc612d2e1873271583c35b63652250d7551d0480f98">
<div>
<select class="usa-select ViewsJumpMenu js-viewsJumpMenu" title="-- Choose --" id="blog-categories-takingm-jump-menu">
<option>-- Choose --</option>
<option data-url="/blogs/taking-measure/categories/249466">Advanced communications</option>
<option data-url="/blogs/taking-measure/categories/248321">Bioscience</option>
<option data-url="/blogs/taking-measure/categories/248371">Buildings and Construction</option>
<option data-url="/blogs/taking-measure/categories/248416">Chemistry</option>
<option data-url="/blogs/taking-measure/categories/248486">Electronics</option>
<option data-url="/blogs/taking-measure/categories/248531">Energy</option>
<option data-url="/blogs/taking-measure/categories/248561">Environment</option>
<option data-url="/blogs/taking-measure/categories/248586">Fire</option>
<option data-url="/blogs/taking-measure/categories/248616">Forensic Science</option>
<option data-url="/blogs/taking-measure/categories/248651">Health</option>
<option data-url="/blogs/taking-measure/categories/249421">Information technology</option>
<option data-url="/blogs/taking-measure/categories/2748236">Infrastructure</option>
<option data-url="/blogs/taking-measure/categories/248866">Manufacturing</option>
<option data-url="/blogs/taking-measure/categories/248946">Materials</option>
<option data-url="/blogs/taking-measure/categories/249011">Mathematics and statistics</option>
<option data-url="/blogs/taking-measure/categories/249051">Metrology</option>
<option data-url="/blogs/taking-measure/categories/249126">Nanotechnology</option>
<option data-url="/blogs/taking-measure/categories/249451">Neutron research</option>
<option data-url="/blogs/taking-measure/categories/249426">Performance excellence</option>
<option data-url="/blogs/taking-measure/categories/249241">Physics</option>
<option data-url="/blogs/taking-measure/categories/249461">Public safety</option>
<option data-url="/blogs/taking-measure/categories/249456">Resilience</option>
<option data-url="/blogs/taking-measure/categories/249341">Standards</option>
<option data-url="/blogs/taking-measure/categories/2813456">Technology transfer</option>
<option data-url="/blogs/taking-measure/categories/249396">Transportation</option>
</select>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</aside>
</div>
</div>
<div class="grid-container">
</div>
</section>
</div>
<div data-elastic-exclude>
<!-- nist-index-ignore-start -->
<footer class="nist-footer padding-bottom-4">
<div class="grid-container nist-footer__info">
<div class="grid-row">
<div class="tablet:grid-col-6">
<div class="nist-footer__logo">
<a href="/" title="National Institute of Standards and Technology" rel="home">
<img class="nist-footer__logo-img" src="/libraries/nist-component-library/dist/img/logo/NIST-Logo-Brand-White.svg" alt="National Institute of Standards and Technology logo" width="300px" height="42px" />
</a>
</div>
<div class="nist-footer__contact">
<h3 class="nist-footer__contact-heading">HEADQUARTERS</h3>
<address>
100 Bureau Drive<br>
Gaithersburg, MD 20899<br>
<a href="tel:301-975-2000">301-975-2000</a>
</address>
<p>
<a href="mailto:do-webmaster@nist.gov">Webmaster</a> | <a href="https://www.nist.gov/about-nist/contact-us">Contact Us</a> | <a href="https://www.nist.gov/visit">Our Other Offices</a>
</p>
</div>
</div>
<div class="tablet:grid-col-6">
<div class="nist-footer__social-links">
<a class="nist-social nist-social--x-white" href=" https://x.com/NIST">
<span>X.com</span>
</a>
<a class="nist-social nist-social--facebook-white" href=" https://www.facebook.com/NIST">
<span>Facebook</span>
</a>
<a class="nist-social nist-social--linkedin-white" href=" https://www.linkedin.com/company/nist">
<span>LinkedIn</span>
</a>
<a class="nist-social nist-social--instagram-white" href=" https://www.instagram.com/nist/">
<span>Instagram</span>
</a>
<a class="nist-social nist-social--youtube-white" href=" https://www.youtube.com/NIST">
<span>YouTube</span>
</a>
<a class="nist-social nist-social--giphy-white" href=" https://giphy.com/nist">
<span>Giphy</span>
</a>
<a class="nist-social nist-social--rss-white" href=" https://www.nist.gov/news-events/nist-rss-feeds">
<span>RSS Feed</span>
</a>
<a class="nist-social nist-social--envelope-white" href=" https://public.govdelivery.com/accounts/USNIST/subscriber/new">
<span>Mailing List</span>
</a>
</div>
<div class="nist-footer__feedback">
How are we doing? <a class="usa-button" rel="nofollow" href="/form/nist-gov-feedback?destination=/blogs/taking-measure/taking-seat-periodic-table" title="Provide feedback">Feedback</a>
</div>
</div>
</div>
</div>
<div class="grid-container">
<div class="nist-footer__nav" role="navigation">
<ul>
<li class="nist-footer__menu-item">
<a href="https://www.nist.gov/privacy-policy">Site Privacy</a>
</li>
<li class="nist-footer__menu-item">
<a href="https://www.nist.gov/oism/accessibility">Accessibility</a>
</li>
<li class="nist-footer__menu-item">
<a href="https://www.nist.gov/privacy">Privacy Program</a>
</li>
<li class="nist-footer__menu-item">
<a href="https://www.nist.gov/oism/copyrights">Copyrights</a>
</li>
<li class="nist-footer__menu-item">
<a href="https://www.commerce.gov/vulnerability-disclosure-policy">Vulnerability Disclosure</a>
</li>
<li class="nist-footer__menu-item">
<a href="https://www.nist.gov/no-fear-act-policy">No Fear Act Policy</a>
</li>
<li class="nist-footer__menu-item">
<a href="https://www.nist.gov/office-director/freedom-information-act">FOIA</a>
</li>
<li class="nist-footer__menu-item">
<a href="https://www.nist.gov/environmental-policy-statement">Environmental Policy</a>
</li>
<li class="nist-footer__menu-item">
<a href="https://www.nist.gov/summary-report-scientific-integrity">Scientific Integrity</a>
</li>
<li class="nist-footer__menu-item">
<a href="https://www.nist.gov/nist-information-quality-standards">Information Quality Standards</a>
</li>
<li class="nist-footer__menu-item">
<a href="https://www.commerce.gov/">Commerce.gov</a>
</li>
<li class="nist-footer__menu-item">
<a href="http://www.science.gov/">Science.gov</a>
</li>
<li class="nist-footer__menu-item">
<a href="http://www.usa.gov/">USA.gov</a>
</li>
<li class="nist-footer__menu-item">
<a href="https://vote.gov/">Vote.gov</a>
</li>
</ul>
</div>
</div>
</footer>
<!-- nist-index-ignore-end -->
</div>
</div>
<script type="application/json" data-drupal-selector="drupal-settings-json">{"path":{"baseUrl":"\/","pathPrefix":"","currentPath":"node\/1246736","currentPathIsAdmin":false,"isFront":false,"currentLanguage":"en"},"pluralDelimiter":"\u0003","suppressDeprecationErrors":true,"back_to_top":{"back_to_top_button_trigger":100,"back_to_top_speed":1200,"back_to_top_prevent_on_mobile":false,"back_to_top_prevent_in_admin":true,"back_to_top_button_type":"image","back_to_top_button_text":"Back to top"},"google_analytics":{"account":"G-HEQ0YF2VYL","trackOutbound":true,"trackMailto":true,"trackTel":true,"trackDownload":true,"trackDownloadExtensions":"7z|aac|arc|arj|asf|asx|avi|bin|bsh|c|csv|doc(x|m)?|dot(x|m)?|dw(fx|g|gd)|dxf|eps|epub|exe|f(90)|flv|gif|gz|gzip|hqx|jar|jpe?g|js|m1v|mp(2|3|4|e?g)|mobi|mov(ie)?|msi|msp|pdf|phps|pl|png|ppt(x|m)?|pot(x|m)?|pps(x|m)?|ppam|sld(x|m)?|thmx|qtm?|ra(m|r)?|rfa|rtf|rvt|sch|sea|sit|swf|tar|tgz|tif|txt|txz|wav|wma|wmv|wpd|wrl|xls(x|m|b)?|xlt(x|m)|xlam|xml|xsd|z|zip"},"nist_search":{"clickTracking":"search-report-click","isDebug":false,"clickTrackEnabled":true,"message":"NIST Search in debug mode. Check the browsers network inspector for Click Track reporting results..."},"data":{"extlink":{"extTarget":false,"extTargetNoOverride":false,"extNofollow":false,"extNoreferrer":false,"extFollowNoOverride":false,"extClass":"ext","extLabel":"(link is external)","extImgClass":false,"extSubdomains":true,"extExclude":"\\.gov\\\/|\\.mil\\\/|\\manufacturingusa\\.com\\\/","extInclude":"","extCssExclude":".ck-editor, .nist-video-thumbnail__lightbox-trigger, a.nist-icon--mail-blue","extCssExplicit":"","extAlert":true,"extAlertText":"Thank you for visiting NIST. We hope your visit was informative. We have provided a link to this site because it has information that may be of interest to our users. NIST does not necessarily endorse the views expressed or the facts presented on this site. Further, NIST does not endorse any commercial products that may be advertised or available on this site. Click OK to be directed to your link.","mailtoClass":"0","mailtoLabel":"(link sends email)","extUseFontAwesome":false,"extIconPlacement":"after","extFaLinkClasses":"fa fa-external-link","extFaMailtoClasses":"fa fa-envelope-o","whitelistedDomains":[]}},"viewsJumpMenu":{"blog-categories-takingm-jump-menu":{"new_window":false}},"ajaxTrustedUrl":{"\/blogs\/taking-measure\/search":true,"\/comment\/reply\/node\/1246736\/comment_node_blog":true},"user":{"uid":0,"permissionsHash":"bd6a443844dbe99b4e6942f3b1397526e760137efd2b1ee6b2d588fc414dff20"},"antibot":{"forms":{"comment-form":{"id":"comment-form","key":"8s3HerPNUiBWAup-NU0eICdfN5XSJ1VRGAW7gyEytXD"}}}}</script>
<script src="/sites/default/files/js/js_jDaFaXhHm6gPUKstNYX9eIyoQXghVs3g7rbR0QoqpYY.js?scope=footer&amp;delta=0&amp;language=en&amp;theme=nist_www&amp;include=eJxdjw2OAyEIhS_klCMRHBlLqzJRpu7efp2fppsmJvg9eI_gaX6i6Xgr-M8fH81F1ZgYqVD6NZkbfAuuSDNcZGhBe0lKAa2OECkRIp3tJsaS16ovhm9h33JodufMY68mTxWzBgjSyI_gJOV5zEBM6ilNlwXuTIHrG7H3_m-Cf2w3QqjbSul24WnMFIssMruXcG_42PKKmcsGB087Tzs7KiZeDa56W7RmN641ru_gk_4AudN_yQ"></script>
<script src="https://siteimproveanalytics.com/js/siteanalyze_6017546.js" async></script>
<script src="/sites/default/files/js/js_yFXzHK1gkl-H3tLPLdnBw5DymsKPJCwJskyq7yQVS6A.js?scope=footer&amp;delta=2&amp;language=en&amp;theme=nist_www&amp;include=eJxdjw2OAyEIhS_klCMRHBlLqzJRpu7efp2fppsmJvg9eI_gaX6i6Xgr-M8fH81F1ZgYqVD6NZkbfAuuSDNcZGhBe0lKAa2OECkRIp3tJsaS16ovhm9h33JodufMY68mTxWzBgjSyI_gJOV5zEBM6ilNlwXuTIHrG7H3_m-Cf2w3QqjbSul24WnMFIssMruXcG_42PKKmcsGB087Tzs7KiZeDa56W7RmN641ru_gk_4AudN_yQ"></script>
<script type="text/javascript">window.NREUM||(NREUM={});NREUM.info={"beacon":"bam.nr-data.net","licenseKey":"37b7ccb661","applicationID":"1089704227","transactionName":"YFxUN0sADEdYVkBaClkWdwBNCA1aFnFGRhVWVWoNVgUHaHpaWkcXWFVaBks9LFtdUGJaAEB6WQ1NEw1YVVBGHltBUFMU","queueTime":4,"applicationTime":1313,"atts":"TBtXQQMaH0k=","errorBeacon":"bam.nr-data.net","agent":""}</script></body>
</html>
Reference in a new issue View git blame Copy permalink