Which has more number of atoms, 100 grams of sodium or 100 grams of iron (given the atomic mass of Na = 23u, Fe = 56 u)?

(a) In 100 grams of Na:

m = 100g, Molar mass of Na atom = 23g, N₀ = 6.022 x 10²³, N = ?

N = (Given mass x N₀)/Molar mass

N = (100 x 6.022 x 10²³)/ 23

N = 26.18 x 10²³ atoms

(b) In 100 grams of Fe:

m = 100 g, Molar mass of Fe atom = 56 g, N₀ = 6.022 x 10²³, N = ?

N = (Given mass x N₀)/ Molar mass

N = (100 x 6.022 x 10²³)/ 56

N = 10.75 x 10²³ atoms

Therefore, the number of atoms is more in 100 g of Na than in 100 g of Fe.