Question

Which of the following sets of orbitals is arranged in order of increasing energy?

• A. 3d < 4s < 4p < 5s < 4d
• B. 4s < 3d < 4p < 5s < 4d
• C. 4s < 3d < 4p < 5s < 4d
• D. 3d < 4s < 4p < 4d < 5s

Answer 1

The correct option is C

4s < 3d < 4p < 5s < 4d

This is based on Aufbau's principle; place the sub shell first which has lower value of (n + l), in case of tie sub shell having lower value of Principal quantum number is always given priority.