Question

For chromium number of electrons present in magnetic quantum number zero is

Answer 1

Chromium; Z=24

Electronic configuration: 1s2, 2s2, 2p6, 3s2, 3p6, 3d5, 4s1

1s, 2s, 2p, 3s, 3p, 3d and 4s are the sub-shells involved.

Each subshell has one orbital for which magnetic qunatum number is zero. Because magnetic quantum has values ranging from -l to +l where l is the Azimuthal quantum number.

For s-subshell, l=0 ∴ values of magnetic quantum number is 0.

For p-orbital, l=1 ∴ values of magnetic quantum number are -1, 0, 1.
For d-orbital, l=2 value of magnetic quantam number are -2,-1,0,1,2
In calcium, 7 orbitals for which magnetic quantum number is zero.but for 3d and 4s ther e is only single electrons because they are half filled .So 12 (5*2 + 1*2) electrons whose magnetic quantum number is zero.