Question

You have 1.6 x 1024 atoms of Bismuth. How many moles are present?

Answer 1

2.66 moles

Explanation:

In order to get from particles to moles or moles to particles, use Avogadro's number (`6.022*10^23`). This number represents the amount of particles of anything in a mole of that substance.

(In other words, a mole of anything is just `6.022*10^23` of that thing. A mole of elephants is `6.022*10^23` elephants. A mole of oxygen atoms is `6.022*10^23` oxygen atoms.)

`mol\es -> particl\es`: multiply by Avogadro's number
`particl\es -> mol\es`: divide by Avogadro's number

We'll divide `(1.6*10^24)/(6.022*10^23)`, and this will give us `~~2.66`.