Question

What is the mass, in grams, of `3.75 xx 10^15` atoms of gold?

Answer 1

`1.227 xx 10^-6` g of gold

Explanation:

`1 " mole " = 6.022 xx 10^23` atoms

Gold's (Au) molar mass from the Periodic table is "196.966" g/mol

Using dimensional analysis:

`3.75 xx 10^15 cancel(" atoms Au ") xx color(red)(cancel(1 mol))/(6.022 xx 10^23 cancel(" atoms Au ")) xx (196.966 " g")/ color(red)(cancel(1 mol)) = (3.75(196.966))/6.022 xx 10^(15-23) = 122.654 xx 10^-8 = 1.227 xx 10^-6 " g Au"`