Answer:
D: (700 L / 22.4 L/mol) (4 g/mol)
Step-by-step explanation:
At STP, Molar volume of a gas = 22.4 L/mol
Now, we are told that helium has a volume of 700 L at STP.
Also, atomic mass of helium = 4 g/mol
Thus, the mass of helium is given as;
(700 L/22.4 L/mol) × 4 g/mol