Given a volume of mercury metal, how do I find its molar quantity?
You need to find (i) the mass of the sample, and (ii) convert this mass into a molar quantity.
You have a 15 mL volume of metal, and so
And then you divide this mass by the molar mass of mercury to get an answer in moles:
The number of moles corresponds to a precise numerical quantity of mercury atoms. You need to use