* Atomic Mass: This is the average mass of an atom of a particular element. It's calculated based on the abundance of isotopes (atoms of the same element with different numbers of neutrons).
* Number of Atoms: The number of atoms in a sample of an element depends on the amount of the sample. For example, a gram of gold has a different number of atoms than a kilogram of gold.
Think of it like this:
* Atomic mass is like the weight of a single apple. It tells you how heavy one apple is on average.
* Number of atoms is like the number of apples in a basket. It depends on how many apples you put in the basket.
To find the number of atoms in a sample, you would use Avogadro's number (6.022 x 10^23 atoms/mol) and the concept of moles.
