Question

Does a `0.10*mol` quantity of oxygen gas contain the same number of atoms as a `0.10*mol` quantity of sodium atoms?

Answer 1

Absolutely not!

Explanation:

`0.1*mol` of dioxygen gas contains `0.2*mol` of oxygen atoms.

`0.1*mol` of sodium atoms (of course) constitute `0.1*mol` of sodium atoms. And thus there are twice as many oxygen atoms as sodium atoms given the stated quantities.

Here we use the mole as simply a number, like 10 or a dozen, or a gross.

Remember, we distinguish between oxygen atoms, and oxygen molecules. This idea of `"molecularity"` is central to the study of inorganic chemistry.