Question

Among the following, the orbitals that have the lowest energy is

• A. 5f
• B. 4f
• C. 6s
• D. 6p

Answer 1

The correct option is C

6s

The energy of any orbital is given by the (n+l) Rule.

Subshell	Azimuthal quantum number
s	0
p	1
d	2
f	3

For 5f: n=5, l=3

n+l=5+3=8

For 4f: n=4, l=3

n+l=4+3=7

For 6s: n=6, l=0

n+l=6+0=6

For 6p: n=6, l=1

n+l=6+1=7

Conclusion statement: Option (c) is the correct answer.