Question

Explain the rules for filling of electrons in different orbitals

Answer 1

You have to study these laws.
1.pauli's exclusion principle
2.aufbu's principle
3.hund's rule

Answer 2

according to Hund's rule orbitals of the same energy are each filled with one electron before filling any with a second also these first electrons have the same spin This rule is sometimes called the bus seating rule