Question

earlier monoatomic and polyatomic ions were called​

Answer 1

Monoatomic: Molecules consist of one kind of atom is called as monoatomic example he, Ne

diatomic molecule: molecule consists of two atoms is call as diatomic molecules example H2, O2, etc.

polyatomic molecules:

molecules consist of of more than two atoms is called as polyatomic molecules.

Sorry,but I don't know the earliest name of Monoatomic and polyatomic molecule