Chapter 17, Problem 1Q

To determine

Among the two which has more atoms.

Answer to Problem 1Q

Number of atoms in $1\text{kg}$ of aluminum is more than iron.

Explanation of Solution

The number of iron and aluminium atom in a pure metal can be found by dividing the mass of the metal by the mass of a single atom of a metal. Take the atomic masses of iron and aluminium from the periodic table and then compare the values.

Write the expression for the number of atoms.

    $N=\frac{\text{mass of the metal}}{\text{mass of single atom of that metal}}$

Here, $N$ is the total number of atoms.

Mass of single atom or atomic mass is inversely proportional to number of atoms in that substance and as mass of iron and aluminium is same.

Atomic mass of aluminium is less than that of iron, therefore no of atoms in $1\text{kg}$ aluminum is more than $1\text{kg}$ iron.

Conclusion:

Thus, Number of atoms in $1\text{kg}$ of aluminum is more than iron.