Q. Which one of the following set of quantum numbers is not possible for electron in the ground state of an atom with atomic number 19?
A) $n = 2,\ l = 0,\ m = 0$
B) $n = 2,\ l = 1,\ m = 0$
C) $n = 3,\ l = 1,\ m = - 1$
D) $n = 3,\ l = 2,\ m = + 2$
Explanation
(d)
$K(Z = 19):1s^{2},\ 2s^{2}2p^{6},3s^{2}3p^{6},4s^{1}$
In the ground state the value of $l$ can be either zero or one.
Hence, the set (d) of quantum numbers $i.e$.,
$(n = 3,\ l = 2,\ m = + 2)$cannot possible in the ground state.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.