How does the mole relate to atoms, molecules and ions?

1 Answer
Mar 24, 2016

Answer:

A mole is simply a quantity of #6.022xx10^23# of anything. We can have a mole of atoms, molecules, ions... or elephants.

One mole of atoms of an element has a mass equivalent to the 'mass number' (now sometimes called 'nucleon number') of that element, e.g. 1 mole of #""_6^12C# has a mass of #12# #g#.

Explanation:

Technically it's slightly more complex than the answer above, because different isotopes have different mass numbers and abundances.

Carbon is mostly #""_6^12C#, with very small amounts of #""_6^13C# and #""_6^14C#, so the relative atomic mass of naturally occurring carbon is very close to #12# gmol^-1#.

On the other hand, naturally occurring chlorine is about #3/4# #""_17^35Cl# and about #1/4# #""_17^37Cl#, so the relative atomic mass of naturally occurring #Cl# is about #35.5#.