What mass of gold (Au) contains the same number of atoms as 2.61 g of aluminum (Al)?

19.11g

Explanation:

mole = mass ÷ molar mass

mole = 2.61 ÷ 27

mole = 0.097mol

Number of atoms in 2.61g of Aluminum = 6.022 × 10^23 × 0.097

= 0.584 × 10^23

= 5.84 × 10^22atoms

To get the same number of atoms for Gold (Au), we multiply the atomic mass of Au by 0.097mol

Atomic mass of Au = 197g/mol

mass = mole × molar mass

mass = 0.097 × 197

mass = 19.109g

mass = 19.11g

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