[tex]\huge\boxed{3.2 Grams}[/tex]
Moles is the unit which measures the amount of substance in the System International (SI). A mole is the amount of substance that contains the same amount of substance as the amount of substance exactly in exactly 12 g of carbon-12. C-12 is the standard to measure moles.
I have attached the Equations for moles.
For this question we will use the formula,
[tex]Moles = \frac{Given Mass}{Atomic Mass}[/tex]
Rearrange the equation,
[tex]Mass = (Moles)x(Atomic Mass)[/tex]
Given:
Moles = 0.2
Molecular Mass of Oxygen Atom(Not molecule) = 16
Thus,
[tex]Mass = (0.2)x(16)\\\\Mass = 3.2 grams[/tex]
The mass of 0.2 moles of oxygen atom is 3.2 grams.