Yes, the word 'non-metal' is a noun, a word for a substance that is not metal; a word for a thing.
The word 'non-metal' can also function as an adjective to describe a noun.
nonmetal
Nails are metal.
nonmetal
nonmetal
FeO is not a nonmetal; it is a compound composed of iron (a metal) and oxygen (a nonmetal).
Fluoride is the ion of fluorine, which is a nonmetal.
Diamond is carbon which is a nonmetal
Nonmetal
nonmetal
Sulfur is a nonmetal.
Sulfur powder is a nonmetal. It is a chemical element with the atomic number 16 and is classified as a nonmetal on the periodic table.
Carbon is a nonmetal. Thus this is a nonmetal oxide.