mass of 2H_{2} explain how
The mass of the compound 2H2 can be determined by adding together the masses of its individual atoms.
The atomic mass of hydrogen (H) is approximately 1.008 atomic mass units (amu). Since there are two hydrogen atoms in the compound, we need to multiply the atomic mass of hydrogen by 2:
2H = 2 * 1.008 amu = 2.016 amu
Therefore, the mass of the 2H2 compound is approximately 2.016 atomic mass units.