Question

The density of copper decreases as temperature increases (as does the density of most substances). Which change occurs in a sample of copper when it is warmed from room temperature to 95 °C?

(a) The sample will become lighter.
(b) The sample will become heavier.
(c) The sample will expand.
(d) The sample will contract.

Answer 1

Upon heating a sample of copper to 95°C, the copper atoms move apart, leading to the expansion of the sample. This occurs because the added energy from heat causes the atoms to require more space. Consequently, the correct answer is that the copper sample will expand.

Step-by-step explanation:

When a sample of copper is warmed from room temperature to 95°C, its density decreases due to the increase in temperature. The decrease in density occurs because the copper atoms require more space as they are provided with additional energy and move away from each other. This movement results in an expansion of the copper sample. Therefore, the correct answer to the question is:

(c) The sample will expand.

It is important to note that while the copper expands, its mass remains the same, so it does not become heavier or lighter, and the expansion is a result of increased space between atoms, not a contraction. Understanding the relationship between temperature and density, as well as the behavior of substances when heated, such as expansion, is crucial in physics.

Answer 2

Answer: Option (c) is the correct answer.

Step-by-step explanation:

As we know that density the amount of mass present in per unit volume.

Mathematically, Density =
`(mass)/(volume)`

So, it means that density is inversely proportional to volume. Hence, when there will be decrease in density of a substance then there will be increase in its volume. That is, expansion of substance will take place.

Also, boiling point of copper is 2,562 degree celsius but we are heating it up to a temperature of 95 degree celsius. This means that copper will remain in liquid state at this temperature.

Thus, we can conclude that a change which occurs in a sample of copper is that copper sample will expand.