Under normal conditions, a gas with a mass of 1.77 g occupies a volume of 10 liters

Under normal conditions, a gas with a mass of 1.77 g occupies a volume of 10 liters. Find the molecular weight of the gas. What is the name of this gas?

Under normal conditions, 1 mol of gas occupies a volume of 22.4 liters. From here we find the number of moles N:
N = 10 / 22.4 = 0.446 mole
Then the molar mass M will be equal to:
M = 1.77 / 0.446 = 3.978
Since a gas molecule consists of two atoms, the mass of one atom is 2.
This is deuterium