The temperature of water in a beaker is 45 °C. What does this measurement represent?

• A. The average kinetic energy of the water molecules.
• B. The amount of heat required to raise the temperature of the water by 1 °C.
• C. The boiling point of water under standard atmospheric pressure.
• D. The total thermal energy contained in the water.

Answer: (A)

Verified step by step guidance

1. Understand that temperature is a measure of the average kinetic energy of the particles in a substance, not the total energy or heat content.
2. Recognize that the temperature of 45 °C indicates how fast, on average, the water molecules are moving or vibrating.
3. Distinguish temperature from heat, which is the energy transferred due to temperature difference, and from boiling point, which is a specific temperature where phase change occurs.
4. Recall that the amount of heat required to raise the temperature by 1 °C is called the specific heat capacity, not the temperature itself.
5. Conclude that the temperature measurement represents the average kinetic energy of the water molecules.