So, if we look on the periodic table, comparing, for example, s to o, if we have s it's below o, what happens to ionization energy as we go down a table?

那么，如果我们看周期表上，比较，比如，硫和氧，硫在氧下面，当我们沿着表向下看的时候,电离能是怎么变化的？

麻省理工公开课 - 化学原理课程节选

If you flip the Periodic Table over you will have the ionization energy of sodium, first ionization energy, 5eV and it is about 5 eV which, when you convert, 496kJ/mol is a whopping 496 kilojoules per mole.

如果浏览周期表,你可以得到钠的离子化能，第一电离能，大约，当你转换的时候，是巨大的。

麻省理工公开课 - 固态化学导论课程节选

And after the periodic table was developed in the late 1800's, people didn't understand this quite as well, they took things a little more literally.

在十九世纪后期元素周期表经过发展之后，人们还没有很好地意识到这一点，他们的认识还有些粗浅。

麻省理工公开课 - 化学原理课程节选