Question

Question #648a7

Answer 1

Either `1.5 * 10^23` `"atoms of oxygen"`, or `1.5 * 10^23` `"molecules of oxygen gas"`.

Explanation:

If there are 0.25 moles of oxygen atoms:
One mole of anything is `6.022*10^23` items of that thing.

The same applies for oxygen atoms! :)
And, if one mole of oxygen is `6.022*10^23` atoms, then `0.25` moles is:

`0.25*(6.022*10^23)=1.5 * 10^23` `"atoms"`.

If there are 0.25 moles of oxygen gas, or `O_2`:
Similarly, if one mole of oxygen gas (`O_2`) is `6.022*10^23` molecules, then `0.25` moles is `1.5 * 10^23` `"molecules"`.

This means there are `2*(1.5 * 10^23)=3.0*10^23` `"atoms"` of oxygen.