Question

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

• A. $12$ and $5$
• B. $12$ and $4$
• C. $12$ and $3$
• D. $12$ and $6$

Answer 1

The correct option is B $12$ and $4$

The configuration of $Cr$ is $1s^2,2s^2,2p^6,3s^2,3p^6,4s^2,3d^4$.

$l=1$ corresponds to p subshell. in the p subshell, there are 12 electrons. $2p^6+3p^6$.

Similarly for $l=2$, there are 4 electrons. $3d^4$.

So, option $B$ is correct.