Question

sta
te and explain hund's rule

Answer 1

The answer to this question involves Hund's rule. Hund's rulestates that: Every orbital in a sublevel is singly occupied before any orbital is doubly occupied. All of the electrons in singly occupied orbitals have the same spin (to maximize total spin).

Answer 2

According to the Hund's rule of maximum multiplicity, the pairing of electrons doesn't takes place in the orbitals of a particular sub shell until all the orbitals of the sub shells first singly filled. The singly occupied orbitals always contain electrons of opposite spin.