Question

Consider the ground state of the Cr atom (Z = 24). The number of electrons with the azimuthal quantum number, $l$ =1 and 2, respectively, are:

• A. 16 and 4
• B. 12 and 5
• C. 16 and 5
• D. 12 and 4

Answer 1

Answer: (B)

12 and 5

Electronic configuration of Cr: 1s${}^2$ 2s${}^2$ 3p${}^6$ 3s${}^2$ 3p${}^6$ 4s${}^1$ 3d${}^5$

$l$ = 1 $\Rightarrow$ p orbtial $\Rightarrow$ 12 electrons

$l$ = 2 $\Rightarrow$ d orbtial $\Rightarrow$ 5 electrons

Hence, the correct option is $B$