Answer:
A.The potential energy increases because the charges have a greater repulsion.
Explanation: Thanks to Mwilliams55513 for the help :}
We use the following formula to calculate the number of atoms:
n (mol) = N(number of atoms) / NA
N(He) = n(mol) · NA
N(He) = 2,0 moles · 6.02·1023 = 12.04·1023 atoms
