Question

Which of the following sets of quantum numbers represent the highest energy of an atom ?

• A. $n=3,l=0,m=0,s=+\frac{1}{2}$
• B. $n=3,l=1,m=1,s=+\frac{1}{2}$
• C. $n=3,l=2,m=1,s=+\frac{1}{2}$
• D. $n=4,l=0,m=0,s=+\frac{1}{2}$

Answer 1

The correct option is C $n=3,l=2,m=1,s=+\frac{1}{2}$

(a) $n=3,l=0$ means $3s-$ orbital and $n+1=3$
(b) $n=3,l=1$ means $3p-$ orbital $n+1=4$
(c) $n=3,l=2$ means $3d-$ orbital $n+1=5$
(d) $n=4,l=0$ means $4s-$ orbital $n+1=4$
Increasing order of energy among these orbitals is
$3s<3p<4s<3d$
$\therefore$ 3d has highest energy.