Answer:
The mass is 20, 89 grams of He
Step-by-step explanation:
We calculate the weight of 1 mol of He, from the atomic weight of each element obtained from the periodic table:
Weight 1 mol He= 4, 0020602 g
1 mol He-----4, 0020602 g
5,22 mol He---x= (5,22 mol He x4, 0020602 g)/ 1 mol He= 20, 89 g