Question

Calculate the number of moles of helium that contains 3.29 × 1021 atoms.

Answer 1

Answer: 0.00546(5) or 5.47 x 10^-3 (don't forget sig figs)

Explanation: A mole of He is 6.02 x 10^23 atoms. To the answer, you'll need to divide 3.28 x 10^21 by 6.20 x 10^23.