Answer:
Between 4s and 3s orbital , 3s has more energy .
Explanation:
According to the rule , the lower the value of (n+l) for an orbital , the lower is it's energy . And if two orbitals have the same value of (n+l), the orbital with lower value of n will have the lower energy .
It depends on the context iorn is a transition metal so it can hold a charge from 1-8