Question

why one mole of hydrogen molecules and one mole of hydrogen atomhave different mases?

Answer 1

Answer:

A MOLE of any substance has the same numerical value for the number of grams it contains as the number of atomic mass units (amu). However, one mole of hydrogen atoms has a mass of 1 gram while one MOLE of hydrogen molecules has a mass of 2 grams. Recall that two hydrogen atoms bind to make a hydrogen molecule

Answer 2

Answer:

A MOLE of any substance has the same numerical value for the number of grams it contains as the number of atomic mass units (amu). ... However, one mole of hydrogen atoms has a mass of 1 gram while one MOLE of hydrogen molecules has a mass of 2 grams. Recall that two hydrogen atoms bind to make a hydrogen molecule.