Question

What violates Hunds?

Answer 1

Answer:

Explanation:

Certain elements when the two sub-shell differ slightly in their energies , an electron may shift from a sub-shell of lower energy to a sub-shell of higher energy only if such a shift results in the symmetrical distribution of the electrons in the various orbitals of the sub-shell of higher energy.

The following two reasons configurations violate Hund's rule :-

1) Symmetrical distribution :- it is well known fact that symmetry leads to stability. Thus, the electronic configurations in which all the orbitals of the same sub-shell are either completely filled or are exactly half-filled are more stable because of symmetrical distribution of electrons.

2) Exchange energy :- The electrons with parallel spins present in the degenerate orbitals tend to exchange their position. The energy released during this exchange is called exchange energy. The number of exchange that can take place is maximum when the degenerate orbitals are completely filled or are exactly half-filled.

Answer 2

Hund's rule states that each subshell in an orbital must be filled with one electron each before anyone is doubly occupied and the spin of all electrons in singly occupied shells is the same. ... This type of electronic configuration violated the Hund's rule.