The particles of a gas are atoms or molecules electrons waves neutrons

Explanation:

A molecule is a substance that contains atoms of either different or same elements.

For example, molecule and NaCl is also a molecule.

On the other hand, a compound always consists atoms of different elements. For example, NaCl is also a compound but is not a compound.

Whereas it is known that gases exist as diatomic molecules. For example, , , are all gases.

Therefore, we can conclude that the particles of a gas are molecules.

The particles of a gas are ATOMS OR MOLECULES.

Hope this helps

it means there are 3 atoms of oxygen