Question

a thermometer is placed in water in order to measure the waters temperature. what would cause the liquid in the thermometer to rise?
the molecules in the water move closer together.
the molecules in the thermometers liquid spread apart.
the kinetic energy of the water molecules decreases.
the kinetic energy of the thermometers liquid molecules decreases.

Explanation:

When the temperature of the thermometer's liquid increases, the kinetic energy of its molecules increases. This causes the molecules to move more vigorously and spread apart. As a result, the liquid expands and rises in the thermometer.

• If the molecules in the water move closer together (first option), it implies a decrease in water temperature, which would not cause the thermometer liquid to rise.
• A decrease in the kinetic energy of water molecules (third option) also means a lower temperature, not conducive to the thermometer liquid rising.
• A decrease in the kinetic energy of the thermometer's liquid molecules (fourth option) would lead to the liquid contracting, not rising.

Answer:

The molecules in the thermometer’s liquid spread apart.