Molecules of which of the following substances is made up of more than one kind of atoms?
The chemical formula for common salt is NaCl, i.e., it has two different atoms - sodium (Na) and chlorine (Cl). If we see the other options then, Chlorine is Cl2, hydrogen is H2, i.e., two hydrogen atoms and neon is Ne. Hence, a molecule of chlorine, hydrogen and neon are made up of only one kind of atoms.