Question

Which is the correct order of increasing energy of the listed orbitals in the atom of titanium?(At. no. Z = 22)

• A. 3s 3p 3d 4s
• B. 3s 3p 4s 3d
• C. 3s 4s 3p 3d
• D. 4s 3s 3p 3d

Answer 1

The correct option is B 3s 3p 4s 3d

This can be solved by using Aufbau Principle.
1s, 2s, 2p, 3s, 3p, 4s, 3d is the increasing energy level.
This can also be arrived at using the $(n+l)$ rule.