Question

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)?

Answer 1

Atomic mass of Na = 23 u (Given)

Then, gram atomic mass of Na = 23 g

Now, 23 g of Na contains = 6.022 x 10²³ number of atoms

`"Thus, 100 g of Na contains "=(6.022xx10^(23))/23xx100" number of atoms"`

                                             = 2.6182 x 10²⁴ number of atoms

Again, atomic mass of Fe = 56 u(Given)

Then, gram atomic mass of Fe = 56 g

Now, 56 g of Fe contains = 6.022 x 10²³ number of atoms

`"Thus, 100 g of Fe contains "=(6.022xx10^(23))/56xx100" number of atoms"`

                                             = 1.0753 x 10²⁴ number of atoms

Therefore, 100 grams of sodium contain more number of atoms than 100 grams of iron.