Question

Of the atoms listed below, which one will have at least one electron in its d orbital?

A. Mg
B. K
C. S
D. Cr
E. none of the above

Answer 1

Answer:

D. Cr

Explanation:

In order to determine which atom has at least one electron in its d orbital, we have to write their theoretical electron configurations.

• ₁₂Mg 1s² 2s² 2p⁶ 3s²

• ₁₉K 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹

• ₁₆S 1s² 2s² 2p⁶ 3s² 3p⁴

• ₂₄Cr 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁴

Cr has 4 electrons in d orbitals. Cr belongs to the d-block in the periodic table.