Question

Determine the number of possible electron arrangements given the following term:

⁴D

please show how you determined the answer

Answer 1

For 4d orbital following are the quantum numbers:

• principal quantum number (n) = 4 (It describe the shell)
• Azimuthal quantum number (L) = 2 (for d orbital L=2, which denotes subshell)
• Magnetic quantum number (m) = -L,0,+L (Hence, -2,-1,0,+1,+2) (It describes orientation of orbital)
• Spin quantum number (s) = +1/2, -1/2 (descibes rotation of electron about its own axis)

According to magnetic quantum number (m), there are total 5 orientations of d-orbital (dxy, dxz, dyz, dx2-y2, dz2).

According to Hund's rule of spin multiplicity, an orbital contain maximum 2 electrons with opposite spin.

Hence, for d-orbital (i.e. 4D);

                        no of orientations of orbitals= 5

                        no of electrons = 5*2 = 10