Question

Which of the following sets of quantam number represents the highest energy of atom?
(A) n=3,l=1,m=1,s=+1/2
(B)n=3,l=2,m=1,s=+1/2
(C)n=4,l=0,m=0,s=+1/2
(D)n=3,l=0,m=0,s=+1/2

Answer 1

Answer:

Atomic orbitals are 4s, 3s, 3p and 3d. (n + l) values being 4, 3, 4 and 5. Hence 3d has highest energy.

Explanation:

The sets of the quantum numbers and the corresponding orbitals are as shown below.

a)n=3,l=0 means 3s− orbital

b)n=3,l=1 means 3p− orbital

c)n=4,l=2 means 4d− orbital

d)n=4,l=0 means 4s− orbital

Increasing order of energy among three orbitals is 3s<3p<4s<4d

∴4d has highest energy.

Hence, the set c of quantum numbers (n=4,l=2,m=1,s=+1/2)  represents the highest energy of an atom.