But the gas can ionize above 2000 degrees.
而气体在2000度以上才能电离。

Too many charge concentrate at a sharp point may ionize the air and produced electric wind.
太多电荷集中在尖角时，会令空气电离，产生电风。

So, for example, in a hydrogen atom, if you take the binding energy, the negative of that is going to be how much energy you have to put in to ionize the hydrogen atom.
例如在氢原子里面，如果你取一个结合能，它的负数就是。