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

Atomic mass of Na = 23u (Given)
Then, gram atomic mass of Na = 23g
Now, 23g of Na contains = 6.022×10²³ number of atoms
Thus, 100g of Na contains = 6.022×10²³ ×100/23 number of atoms
= 2.6182 × 10²⁴ number of atoms
Again, atomic mass of Fe = 56u (Given)
Then, gram atomic mass of Fe = 56g
Now, 56 g of Fe contains = 6.022×10²³ number of atoms
Thus, 100 g of Fe
6.022×10²³ ×100/56 number of atoms
= 1.0753 × 10²⁴number of atoms
Therefore, 100 grams of sodium contain more number of atoms than 100 grams of iron.

For more answers visit to website:
https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-3/