The liquid in a thermometer move up the glass tube when the air temperature?

The liquid in a thermometer rises in the glass tube when the air temperature increases due to thermal expansion. As the temperature rises, the liquid (usually Mercury or alcohol) absorbs heat and expands, occupying more space and causing it to move upward in the tube. This movement allows the thermometer to accurately reflect the ambient temperature. Conversely, when the temperature drops, the liquid contracts and moves down the tube.