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`)?

Explanation

In order to solve this problem, we should convert 100 grams of sodium into moles of sodium, and also 100 grams of iron into moles of iron. The element having more moles will have more atoms.
Please note that since the atomic mass of sodium is 23 u, the molar mass of sodium will be `23 g//"mol"`
Similarly, sinc the atomic mass of iron is 56 u, the molar mass of iron will be `56 g//"mol"` . We will now calculate the moles of sodium atoms (Na) and iron atoms (Fe), one by one.
(i) Moles of sodium `= ("Mass of sodium")/("Molar mass of sodium")`
`= 100/23`
(ii) Moles of iron `= ("Mass of iron")/("Molar mass of sodium")`
`= 100/56`
`= 1.78`
We find that 100 grams of sodium contains 4.34 moles of atoms wheares 100 grams of iron contains 1.78 moles of atoms. Sine 100 grams of sodium has more moles, it contains more atoms than `100` grams of iron.