What is the mass of 12.01 moles of hydrogen gas(H2)

24.2109 g

Explanation:

Hydrogen has a molar mass of 1.007947 g/mol so since hydrogen gas has 2 hydrogens, you can multiple this by 2 and then multiply that by 12.01 to get the total mass of 12.01 moles of hydrogen gas.

water is used to store them because it would keep the radiation from getting out in the open and causing harm to the workers

away from the curb

explanation:

the wheels would then hit the curb if it started to rolling, decreasing the chance of an accident.