Mole concept provides a relationship between number of particles(atoms) and their mass. Thus it is possible to calculate the number of particles in a given mass.

Molar mass of Zinc(Zn) = 65g

Given Mass of the Zinc = 10g

As we know that, Number of moles = mass of an element/molar mass of an element

Hence Number of moles= 10g/65g = 0.15 moles.

Since 1 mol of zinc contains 6.02 × 10²³ atoms

Therefore, 0.15 mol of zinc contains = 6.02 × 10²³ × 0.15 mol = 9.03 × 10²² atoms of zinc