A mole (Avogadros number) is the number that is equivalent to the number of atoms in 12 grams of pure carbon-12, which is always 6.022 x 1023 atoms. Hydrogen has an atomic weight of 1.0079 rather than 1.0000 because a small proportion of hydrogen atoms are the isotope deuterium, or hydrogen-2, which has one proton and one neutron rather than just one proton. An even smaller proportion of hydrogen atoms are the isotope tritium, or hydrogen-3, which has one proton and two neutrons. These isotopes with an additional neutron add a tiny amount to hydrogens average atomic weight.The atomic weight of hydrogen is 1.0079, which means that one mole of hydrogen atoms (or 6.0221 x 1023 atoms of hydrogen) has a mass of 1.0079 grams. So, if there is 1.0079 grams of hydrogen per mole, then you can find out the number of hydrogen atoms in 1.0000 grams using the following proportion:6.0221 x 1023 atoms H / 1.0079 g H = x atoms H / 1.0000 g HMultiply both sides of the equation by 1.0 g H to isolate the variable x onthe right side.1.0000 g H * (6.022 x 1023 atoms H / 1.0079 g H) = x atoms HSimplify and cancel terms.6.0221 x 1023 atoms H / 1.0079 = x atoms HMultiply and round the answer to 5 significant figures.5.9749 x 1023 atoms H / 1.0000 g H
Because the molecular mass of Hydrogen is 1gram/mole, there is 1 mole of hydrogen in 1 gram of hydrogen atoms.For every mole, there are 6.02*10^23 atoms so in 1 gram of hydrogen there are 6.02*10^23 hydrogen atoms (in scientific notation) this is equal to 602000000000000000000000 hydrogen atoms.
Hydrogen has an atomic mass of 1.01 atomic mass units. An atomic mass unitis TINY. One gram is equal to about 600000000000000000000000 amu (or 6followed by 23 zeros). So, because the mass of hydrogen is close to 1 amu,1 gram of hydrogen contains about that same huge number of atoms.
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