That is to say the ionization energy of the second most electron.
这是二级电离能，这就是说，电子数第二多的电离能。
2
One major difference between electron affinity and ionization energy is that when we talked about ionization energy, remember ionization energy always has to be positive.
电子亲和能，与电离能之间最大的不同就在于，当我们提到电离能的时候，记得电离能总是正的。
3
So, second ionization energy simply means you've already taken one electron out, now how much energy does it take for you to take a second electron out.