Ground state atomic calcium $($Ca$)$ has electronic configuration $[$Ar$]4$s$2$

$.$

Excitation of the element involves the promotion of an electron and gives rise to

a $[$Ar$]4$s$1$

$4$p$1$

electronic configuration.

$($i$)$ Obtain the states arising from both configurations, $[$Ar$]4$s$2$ and $[$Ar$]4$s$1$

$4$p$1$

$.[10$ marks$]$

$($ii$)$ Order the states derived in part $($i$)$ from the lowest to the highest energy