Question

The number of electrons with magnetic quantum number value zero in chromium $(Z=24)$ atom is

• A. $6$
• B. $7$
• C. $11$
• D. $12$

Answer 1

The correct option is D $12$

Solution:

First we have to write electronic configuration of Chromium atom, whose atomic number =$24$

$C{r}_{24}=1s^2,2s^2,2p^6,3s^2,3p^6,4s^1,3d^5$

We have to find total electrons with $m_l=0$

$s$ orbitals has $m_l=0$

So total $7s$ electrons are present, $2$ electrons in $2p$ and $2$ electrons in $3p$ has $m_l=0$, $1$ electrons in $3d$ has $m_l=0$

Total $12$ electrons which hasve $m_l=0$

Option D is correct answer.