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 a thermometer is placed in water, heat is transferred from the water to the thermometer's liquid (usually mercury or alcohol). This causes the molecules of the thermometer's liquid to gain kinetic energy. As a result, the molecules spread apart (thermal expansion), which makes the liquid rise in the thermometer.

• Option 1: If water molecules move closer together (compression), it doesn't directly cause the thermometer liquid to rise.
• Option 3: A decrease in water molecules' kinetic energy (lower temperature) would not cause the thermometer liquid to rise.
• Option 4: A decrease in the thermometer's liquid molecules' kinetic energy would lead to contraction, not expansion.

Answer:

The molecules in the thermometer's liquid spread apart.