Question

Using the Kinetic Molecular Theory of Matter, explain what is happening to the liquid in a thermometer when it measures something that is hot. What about when it measures something that is cold?

Answer 1

When the thermometer measures something hot, the kinetic energy of the liquid particles in the thermometer increases, causing them to move faster and take up more space. This increases the volume of the liquid and the thermometer indicates a higher temperature. When the thermometer measures something cold, the kinetic energy of the liquid particles decreases, causing them to move slower and take up less space. This decreases the volume of the liquid and the thermometer indicates a lower temperature.

Answer 2

When heated, the molecules of the liquid in the thermometer move faster, causing them to get a little further apart. This results in movement up the thermometer.