# What is the electron configuration of "H"^-?

Well, what's the configuration of $\text{H}$ plus one electron? $\text{H}$ notoriously has only one electron... and it is in the $1 s$ orbital, the first orbital of $n = 1$ and $l = 0$. Therefore, its electron configuration can only be $1 {s}^{1}$.
...and ${\text{H}}^{-}$ has $1 + 1 = 2$ electrons by conservation of charge... so 1s^? is the electron configuration?