Question

If you drew a graph for second ionization energy, which element woul you have to omit? Why?

Answer 1

Well, of course you would have to exclude the hydrogen atom. Why?

Explanation:

First ionization, both the atom and the cation are specified to be in the gas phase:

`H(g) +Delta rarr H^(+)(g) + e^-`

But the hydrogen cation ain't got no more electrons; and thus it cannot have a second ionization event.