Question

How many atoms are contained in 0.55 moles of Br?

Answer 1

`0.55xxN_A` `"bromine atoms.........."`

Explanation:

Where `N_A="Avogadro's Number,"` `6.022xx10^23*mol^-1`.

And thus, `0.55*cancel(mol)xx6.022xx10^23*cancel(mol^-1)=3.31xx10^23` `"bromine ATOMS"`.

Note that here we use the mole as would use any other collective term, i.e. dozen, score, gross............Of course the mole specifies a much larger quantity of stuff.

Also note that we specify a quantity of `0.55` `mol` `"bromine atoms"`. A quantity of `0.55` `mol` `"bromine molecules"` would contain TWICE this number of bromine atoms. Why?