the old fashioned kilocalories/mol,

老式的千卡/摩尔
which American organic chemists like to use.

美国搞有机化学的人喜欢用这个单位
Some day it'll change to kilojoules/mol,

总有一天会换成千焦/摩尔
but for me it's still kilocalories/mol.

我一直都用千卡/摩尔
Okay, this is a logarithmic scale, so it covers a very wide range.

这是能量的指数级的范围非常广
Now Coulomb, if you have a proton and an electron,

根据库伦定律一个质子和一个电子
as far apart as the distance of the carbon-carbon bond,

若它们间的距离与一个碳碳键相当
that's 216 kilocalories/mol,

它们间的能量是216 千卡/摩尔
right in the middle of this, or near the middle.

大小刚好落在这个能量轴的中间偏右
Magnetic interaction is much weaker.

磁作用的能量要弱得多
If you have two electron spins, at the same distance from one another,

相距亦为一个碳碳键长度的两电子自旋间
their energy is what?

能量有多少呢