Question

calculate no of atoms in 3.2g o f sulphur

Answer 1

Number of moles in 3.2 grams of Sulphur = 3.2/32 = 0.1 moles

1 mole contains Avogadro number of S atoms
0.1 moles contain →0.1(Avogadro number) of S atoms
                             → 0.1(6 x 10²³) S atoms
                             → 6 x 10²² Sulphur atoms

Therefore 3.2 grams of sulphur contains 6 x 10²² atoms of sulphur.