Question

Which has more number of atoms: 100g of sodium or 100g of iron?

(Atomic mass of Na = 23u, Fe = 56u)?

• A. Sodium
• B. Iron
• C. Both have equal number of atoms
• D. Data insufficient

Answer 1

The correct option is A Sodium

Moles of sodium = 100/23, moles of iron = 100/56
Number of atoms = Moles x Avogadro number.

As moles of sodium are greater than moles of Iron, therefore, a number of atoms of sodium are greater than the number of atoms of iron.