Question

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

Answer 1

Atomic mass of Na=23u
Then gm atomic mass of Na=23g
Now 23g of Na contains=6.022×10²³ g number of atoms
Thus 100g of Na contains=(6.022×10²³×100)/23 no of atoms=2.61×10^{24 g} No of atoms

Again
Atomic mass of Fe=56u
Then gm atomic mass of Fe=56g
Now 56g of Fe contains=6.022×10²³ g number of atoms
Thus 100g of Fe contains=(6.022×10²³×100)/56 no of atoms=1.07×10^{24 g} No of atoms
Therefore 100 gms of sodium contains more number of atoms than 100 gms of Iron