Question

The 4s subshell has more energy than 3p subshell. 

(a) Is it true? Justify your answer. 

(b) State Aufbau principle.

Answer 1

(a) Yes. For both 4s and 3p subshells the (n+l) value is 4. But 4s, with high value of ‘n’ has higher energy. 

(b) Aufbau principle – In the ground state of the atoms, the orbitals are filled in order of their increasing energies.