Question

Which of the following orbitals has the highest energy?

• A. $5d$
• B. $5f$
• C. $6s$
• D. $6p$

Answer 1

Answer: (B)

$5f$

The orbital energies are compared with the help of $n+l$ rule. The higher value of $n+l$, higher is the energy of the orbital.

$5d=n+l=7$

$5f=n+l=8$

$6s=n+l=6$

$6p=n+l=7$

The $n+l$ value is greatest for 5f orbital.

Hence it has the highest energy among the given options.