What happens to mercury in response to temperature changes?

The correct answer reflects the behavior of mercury as a metal in response to temperature changes. Mercury is a unique substance because, unlike most metals, it is liquid at room temperature. When temperature decreases, mercury contracts, meaning it takes up less volume; conversely, when temperature increases, it expands and takes up more space. This property of thermal expansion and contraction is typical for most liquids and helps illustrate fundamental principles of thermodynamics.

The behavior of mercury in response to temperature does not allow it to evaporate in cold temperatures, freeze in heat, or remain constant regardless of temperature, which highlights the correctness of the expansion and contraction response. Understanding these properties can be quite important in practical applications, such as in thermometers where mercury is used to measure temperature changes accurately.