Question

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

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

Answer 1

The correct option is B $12$ and $5$

The electronic configuration of $Cr$ atom $=1s^2$ $2s^2$ $2p^6$ $3s^2$ $3p^6$ $3d^5$ $4s^1$

For $l=1,$ $2p^6,3p^6$

$=12e^{-}$

For $l=2,$ $3d^5$

$=5e^{-}$

So, the correct option is $B$