Question

1. explain how does density vary with temperature?

Explanation:

For most substances, when temperature increases, volume expands (due to increased kinetic energy of particles causing them to move more and occupy more space) while mass remains constant. Since density = mass/volume, an increase in volume leads to a decrease in density. For water, it's an exception around 4°C. Below 4°C, as temperature rises, water contracts and density increases until 4°C where density is maximum. Above 4°C, further heating causes expansion and density decreases.

Answer:

For most substances, density decreases with an increase in temperature. Water has a unique behavior, with density increasing from below 4°C up to 4°C and then decreasing above 4°C.