# How many oxygen atoms are there in a half mole quantity of carbon dioxide?

In a $\frac{1}{2}$ mole of $C {O}_{2}$? Well, clearly there are 1 mole of oxygen atoms.
In one mole of $C {O}_{2}$, clearly there are $2$ mole of oxygen atoms; note that I speak in terms of atoms, and not molecules, and I am perfectly free to do so in the context of this question.
So in a $\frac{1}{2}$ mole of $C {O}_{2}$, there are $1$ mol of oxygen atoms. What are the masses of each quantity?