Question

Which one of the following species is diamagnetic in nature?

• A. $H_2^{-}$
• B. $H_2^{+}$
• C. $H_2$
• D. $H{e}_2^{+}$

Answer 1

Answer: (C)

A species is said to be diamagnetic if all the electrons present in it are paired.

Species	Electrons	MO Electronic configuration	Magnetic behaviour
$H_2$	3	$\sigma 1s^2\stackrel{\ast }{\sigma }1s^1$	Paramagnetic
$H_2^{+}$	1	$\sigma 1s^1$	Paramagnetic
$H_2$	2	$\sigma 1s^2$	Diamagnetic
$H{e}_2^{+}$	3	$\sigma 1s^2\stackrel{\ast }{\sigma }1s^1$	Paramagnetic