Question

Which of the following statements is correct?

(a) The electronic configuration of Cr is (Ar) 3d⁵ 4s¹.

(b) The magnetic quantum number may have a negative value.

(c) In the ground state of an atom, the orbitals are filled in order of their increasing energies.

(d) The total number of nodes are given by n − 2.

Choose the most appropriate answer from the options given below:

Options

• (a), (c) and (d) only

• (a) and (b) only

• (a) and (c) only

• (a), (b) and (c) only

Answer 1

(a), (b) and (c) only

Explanation:

(a) The electronic configuration of Cr is [Ar] 3d⁵ 4s¹ is correct.

(b) The magnetic quantum number may have a negative value because it depends upon the azimuthal quantum number so, m = – l to + l is correct.

(c) According to the Aufbau principle, the ground state of an atom, the orbitals are filled in order of their increasing order of their degenerate energy levels so, this statement is also correct.

(d) The total number of nodes are given by n – 1 so, this statement is incorrect.