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

Nov 3, 2016

Absolutely not!

#### Explanation:

$0.1 \cdot m o l$ of dioxygen gas contains $0.2 \cdot m o l$ of oxygen atoms.

$0.1 \cdot m o l$ of sodium atoms (of course) constitute $0.1 \cdot m o l$ 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 $\text{molecularity}$ is central to the study of inorganic chemistry.