Elements with valency 1 are

Options

A. always metals
B. always metalloids
C. either metals or non-metals
D. always non-metals

Answer

C

Explanation

Metals and non-metals both can have valency 1.
Metals which have 1 valence electron and non-metals which have 7 valence electrons, have valency 1. It is because, metals loose their `1e^(-)` and non-metals gain `1e^(-)` to complete their octet.