Why does water heat up and cool down slowly compared to many other substances?

• A. Because water molecules are lighter and move faster than those in other substances.
• B. Because water easily undergoes phase changes at room temperature.
• C. Because water has a high specific heat capacity, requiring more energy to change its temperature.
• D. Because water is a poor conductor of heat.

Answer: (C)

Verified step by step guidance

1. Understand the concept of specific heat capacity, which is the amount of heat energy required to raise the temperature of 1 gram of a substance by 1 degree Celsius. It is a measure of how much energy a substance can store as heat.
2. Recognize that water has a relatively high specific heat capacity compared to many other substances. This means it can absorb or release a large amount of heat with only a small change in temperature.
3. Consider the molecular structure of water, which allows for extensive hydrogen bonding. These hydrogen bonds require additional energy to break or form when the temperature changes, contributing to water's high specific heat capacity.
4. Relate this to the heating and cooling process: because water requires more energy to change its temperature, it heats up and cools down more slowly than substances with lower specific heat capacities.
5. Conclude that the correct explanation for why water heats and cools slowly is due to its high specific heat capacity, not because of molecular weight, phase changes at room temperature, or thermal conductivity.