Question

which of the following metals is diamagnetic?
a) potassium
b) lithium
c) barium
d) cesium

Explanation:

Diamagnetic substances have all electrons paired. Alkali metals (Potassium, Lithium, Cesium) have one unpaired electron (group 1, valence electron \(ns^1\)) and are paramagnetic. Barium (group 2, electron configuration ends with \(6s^2\), all electrons paired) is diamagnetic.

Answer:

C) Barium