Answer: 0.05 moles
Step-by-step explanation:
To convert from atoms to moles, you will need Avogadro's number.
Avogadro's number: 6.022×10²³atoms/moles
(3.13×10²²atoms)×(moles/6.022×10²³ atoms)=0.05 moles
The atoms would cancel out and we will be left with our moles.