Question

Though the five $d$-orbitals are degenerate, the first four $d$-orbitals are similar to each other in shape whereas the fifth $d$-orbital is different from others. What is the name of the fifth orbital?

• A. $d_{x^2-y^2}$
• B. $d_{z^2}$
• C. $d_{xz}$
• D. $d_{xy}$

Answer 1

Answer: (B)

The five $d$-orbitals are $d _{ xy }, d _{ yz }, d _{ zx }, d _{ x ^{2}- y ^{2}}, d _{ Z ^{2}}$
and have shapes as given in the figure. It is clear that $d _{ Z ^{2}}$-orbital has one lobe along $z$ axis and donut-shape electron ring while all other d-orbitals have two dumbells.