IUPAC Gold Book - ionization energy, (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){(i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)})(window,document,'script','https://www.google-analytics.comanalytics.js','ga');ga('create', 'UA-82507018-1', 'auto');ga('send', 'pageview'); Ei

Entry history for ionization energy, $E i$

Date	Update description
2006-09-29	Taken from the original Gold Book, published in version 1.0.0 of the XML Gold Book.