Question

Arrange in the increasing number of radial nodes: 3p, 4s, 1s, 5d.

(a) 1s < 3p < 4s < 5d

(b) 1s < 4s < 3p < 5d

(c) 1s < 3p < 5d < 4s

(d) 5d < 1s < 3p < 4s

This question was addressed to me in final exam.

My question is based upon Electron Probability Density in division Quantum Physics of Engineering Physics I

Answer 1

Correct answer is (c) 1s < 3p < 5d < 4s

To explain: The radial nodes in an orbital is given by n – l -1. For 3p it is 2, for 5d it is 3, for 4s it is 4 and for 1s it is 1. Thus, the correct order is: 1s < 3p < 5d < 4s.