Calculate the number of sulphur atoms in 64g of sulphur

The molar mass for sulphur is 32g/mol, therefore the number of moles is 64g ÷ 32 g/mol = 2 mol. 1 mol = 6.02 × 10^23, so there are 2 × 6.02 × 10^23 = 1.204 × 10^24 atoms.

the density of gold = 19.3 g/cm3

the relation between density and mass and volume is

density = mass / volume

given :

mass of gold = 13 g

density = 13g / volume = 19.3

volume = 13 /19.3 = 0.67 cm^3

thus volume of gold nugget = 0.67 cm^3