The wavefunction for the electron in its lowest energy state in the ion $H{e}^{+}$is proportional to $e^{-2\frac{r}{a_0}}($i$.$e$.=N{e}^{-2\frac{r}{a_0}}).$ Normalize $.$

Standard integral:

${\displaystyle \underset{0}{\overset{}{}}}{x}^n{e}^{-ax}dx=\frac{n!}{a^{n+1}}$

where $n!$ denotes a factorial: $nn(n-1)(n-2)dots1$