How would you calculate the number moles of calcium in 27.0 g of Ca?
#27.0 g Ca x (1 mol Ca)/(6.022 x 10^23 Ca) = ?#
Simply divide thru by the molar mass.........and multiply by
We KNOW that
And thus we can use this mass as a measure of the NUMBER of calcium atoms we possess.......i.e.
And we get the answer as a DIMENSIONLESS NUMBER as required.