Why one mole of hydrogen molecules and one mole of H-atoms have different masses?

The number of grammes in a MOLE of any material is the same as the number of atomic mass units (amu). A mole of hydrogen atoms, on the other hand, has a mass of 1 gramme, while a mole of hydrogen molecules has a mass of 2 grammes. Remember that a hydrogen molecule is made up of two hydrogen atoms bound together.

Explanation:

i don't see a text, but i am gonna assume this *orbit* the curved path, usually elliptical, described by a planet, satellite, spaceship, etc., around a celestial body, as the sun.