Can someone explain why 56g of iron is 1 Mol? Watch
but why is 1g of hydrogen = 1 mole or 2 grams of helium=1 mole.
2 = 1 pair
12 = 1 dozen
6.022x1023 = 1 mole
6.022x1023 of any atoms is 1 mole
So if the atomic/molecular number of a thing is some number n, then a mole of it will weigh n grams.
Iron has a mass number of 56, so a mole of iron atoms will have a mass of 56g.
Works with molecules too. CO2 has a relative molecular mass of 44 (12 + 16 + 16) so a mole of CO2, or Avogadro's number of CO2 molecules, will have a mass of 44g.
1mol Carbon is 12g
1 mol Oxygen is 16g