Question

Among the following, the energy of 2s orbital is lowest in:
1. K
2. H
3. Li
4. Na

Answer 1

Correct Answer - Option 1 : K

Concept:

As the value of Z (atomic number) increases, the energy of orbitals decreases (becomes more negative value)

The energy of 2s orbital is lowest in K (potassium)

Therefore, the order of energy of 2s orbital is H > Li > Na > K