Question

define and explain hund's rule? with example

Answer 1

Answer:

When assigning electrons to orbitals, an electron first seeks to fill all the orbitals with similar energy (also referred to as degenerate orbitals) before pairing with another electron in a half-filled orbital. Atoms at ground states tend to have as many unpaired electrons as possible. In visualizing this process, consider how electrons exhibit the same behavior as the same poles on a magnet would if they came into contact; as the negatively charged electrons fill orbitals, they first try to get as far as possible from each other before having to pair up.

Explanation:

Answer 2

Answer :

According to Hund's rule, one electron per orbital is placed within a sublevel before pairing them.

Since there are three p, five d and seven f orbitals. Thus, the pairing of electrons will start in p, d and f orbitals with the entry of 4th, 6th and 8th electron respectively.

For example :

The electron configuration for carbon atoms is: $1s^22s^22p^2$

The two electrons present in 2s will occupy the same orbital, whereas the two electrons present in 2p will be in different orbital (that means the electrons aligned in the same direction) in accordance with Hund's rule.