A single atom of platinum has a mass of 3.25 x 10^-22 g. What is the mass of 6.0 x 10^23 platinum atoms?

3.25 x 10^-22 g/atom times 6.0 x 10^23 atoms/mole = the answer you seek

The answer is 1.95 * 10² g

1 atom = 3.25 * 10⁻²² g

6.0 * 10²³ atoms = x g

1 atom : 3.25 * 10⁻²² g = 6.0 * 10²³ atom : x

x = 3.25 * 10⁻²² g * 6.0 * 10²³ atom : 1 atom

x = 3.25 * 6 * 10²³⁻²² g

x = 19.5 * 10 g

x = 1.95 * 10 * 10 g

x = 1.95 * 10² g