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

Given, Atomic mass of Na=23u

Atomic mass of Fe= 56u

Now,
23g of Na contains \( = 6.022 × 10^{23} \) atoms

1g of Na contains = \( 6.022 × 10^{23} \over 23 \)atoms

100g of Na contains = \( 6.022 × 10^{23} \over 23 \) × 100 \( = 2.6182 × 10^{24} \) atoms

Now, 56g of Fe contains = 6.022 × 1023 atoms

1g of Fe contains = \( 6.022 × 10^{23} \over 56 \)atoms

100g of Fe contains = \( 6.022 × 10^{23} \over 56 \) × 100 \( = 1.075 × 10^{24} \) atoms

Hence 100g of Na has more atoms.