D And F Block Elements

$3 d^4 4 s^2 ; 3 d^{10} 4 s^1$

$3 d^5 4 s^1 ; 3 d^{10} 4 s^1$

$3 d^5 4 s^1 ; 3 d^9 4 s^2$

$3 d^4 4 s^2 ; 3 d^9 4 s^2$