Question

How does Avogadro's number relate to atomic mass?

Answer 1

The atomic mass tells you have many grams there are per mole of something.

1 mole contains approximately `6.02*10^23` atoms or molecules (depending on what is being talked abotu, whether number of water molecules, atoms of magnesium or total atoms in `"NaCl"`)

So for example, water has a mass of around `18g` `mol^-1`, this means that 18g of water contains `6.02*10^23` water molecules, but `1.806*10^24` atoms (three atoms per water molecule).

Anther example, magnesium has a mass of around `24.3g` `mol^-1`, and 10g contains `10/24.3~~0.412mol` of Mg. `0.412(6.02*10^23)~~2.48*10^23` atoms