Question

If the temperature of an iron sphere is increased

Answer 1

Answer: its density will decrease

By increasing the temperature of the iron sphere, its volume will increase (due to the material of which it is composed), this is a phenomenon known as thermal dilation. However, the mass of the sphere will remain the same.

On the other hand, density $D$ is a characteristic property of substances and materials and is defined as the relationship between the mass $m$ and volume $V$ of a specific substance or material, as shown below:

$D=\frac{m}{V}$

This means density is inversely proportional to volume. Therefore, increasing the temperature of the iron sphere, its volume will be increased and its density will be decreased.