Question

Which has more atoms, 200 grams of sodium or 200 grams of iron?
(given :- Atomic mass of Na = 23 u, Fe = 56 u)

Answer 1

Atomic mass of Na = 23 u (Given)
Then, gram atomic mass of Na = 23 gm
Now, 23 gm of Na Contains = 6.022 x 10²³ number of atoms
Thus, 200 gm of Na contains $=\frac{6.022\times {10}^{23}}{23}\times 200=52.36\times {10}^{23}$ atoms
Now in the second case,
The atomic mass of Fe = 56 u (Given)
Then, the gram atomic mass of Fe = 56 gm
Now, 56 gm of Fe contains = 6.022 x 10²³ number of atoms
Thus, 200 g of Fe contains $=\frac{6.022\times {10}^{23}}{56}\times 200=21.5\times {10}^{23}$ atoms
So, the number of atoms are more in 200 gm of Na than in 200 gm of Fe.