Discuss Bohr's Bury's rules.

Explanation

Bohr.s Bur.s rules : These rules are related to the energy of subshells. These are as follows:
Rule 1- : The orbital having low (n+l) value lowest energy. Example , For 4 s orbitla `n + l = 4 + 0 =4`
For 3 d orbitla, `n + l = 3 + 2 = 5`
So, the 4s orbital has lower energy then 3 orbital.
Rule 2, If two subshells have same value of (n+l) then the subshell with lower value of .n. has lower energy.
Example: For 4f subshell, `n + l = 5 + 2 = 7`
For 5d subshell,` n + l = 5 + 2 = 7`
But the value of n is lesser for 4f than 5d. Therefore, 4f has lower energy than 5d.