Question

calculate the number of atoms in 2g of oxygen

Answer 1

no of mole = given wt /molecular wt
= 2/16 = 1/8

no of atoms = no of mole × Avogadro constant
= 1/8 × 6.023 × 10²³

= 6.023/8 × 10²³

=0.75 × 10²³ (approx)

Answer 2

number of atom = mole * Avogadro' number(Na) * atomicity

mole = mass/molecular mass
= 2/16
=1/8
atomicity of molecule = 1
Avogadro'number = 6.023 * 10^23
number of atom = 1/8 * 6.023 * 10^23 * 1
= 0.75 * 10^23