How many atoms are in a mole of oxygen ... how many molecules are in a mole of caffenine ... how much does a mole od diatomic nitrogen weigh

One mole of any substance contains 6.02 x 10²³ particles.

One mole of oxygen has 6.02 x 10²³ atoms

One mole of caffeine has 6.02 x 10²³ molecules

One mole of diatomic nitrogen contains two moles of nitrogen atoms. Atomic mass of nitrogen is 14 g. Thus,

Mass of diatomic nitrogen = 2 x 14 = 28 g