The molar mass of a diatomic gas 28 g.mol^-1. The gas is quite likely __ 

The mass of a single atom of an element. 

The mass of one twelfth the mass of a carbon-12 atom.

The mass (in g) of 1 mole of ammonia, NH₃, is __ 

The mass of 1 mole of  atoms of an element. 

Fill in the blank: The value of 2 mole of atoms is __ x 10²⁴ atoms

The mass (in g) of 0,5 moles of H₂SO₄ is ___

The name of the person associated with one mole.