How many molecules are in 15 moles of CO2?

Mole is a unit for measuring a large number of very small entities, like atoms, molecules, ions, etc. And 1 mole of substance is equal to 6.02214076 × 10^23. So if there is 1 mole of CO2, that means we have 6.02214076 × 10^23 CO2 molecules of CO2 in 1 mole of CO2.

Explanation:

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

the answer is option a.