Answer:
Option a. 4 g of He
Explanation:
6.02×10²³ is the Avogadro's number. The amount of units that corresponds to 1 mol, in this case the units are molecules.
Let's find out which mass corresponds to 1 mol (mass / molar mass)
a. 4g / 4g/mol = 1 mol He
b. 14g / 6.94 g/mol = 2.01 mol Li
c. 80g /159.8 g/mol = 0.5 moles Br₂
d. 4g / 2g/mol = 2 mol H₂
