Depending on Atmospheric Pressure
A mercury thermometer can go down to -30 deg C
The mercury on a medical thermometer does not go down when removed from the body because the mercury expands to a certain level when it comes in contact with body heat, and even after it's removed, it does not contract back immediately. The thermometer needs to be shaken or reset for the mercury to go back down to its starting point.
Change in temperature is what cause the Mercury to expand up (hotter) or shrink down (colder).
the heat and temperature that causes it to rise and fall.
As tempertature rises, the Mercury in the thermometer expands, causing it to go up. As temperature decreases, the mercury in the thermometer contracts, causing it to go down on the scale. However, mercury thermometers are very dangerous if it breakes and gets on your skin. so it it reccomended to use an electric thermometer. these thermometers use thermoelectric current to measure temperature. ergo. they are safe if they break cheers <3 -Eli
When it's cold, the molecules in the mercury slow down and become more compact, leading to a decrease in volume. This reduction in volume results in the mercury level dropping in a thermometer.
The exterior of the bulb of the thermometer expands first, resulting in the mercury level to go down. After that the mercury in the bulb expands more than the glass bulb, resulting in the subsequent rise of the mercury level.
In a mercury thermometer, the mercury expands when it is heated, causing it to rise in the thermometer's narrow tube. This increase in volume is a physical property of mercury known as thermal expansion. The height of the mercury column in the thermometer is then used to measure the temperature.
An Alcohol thermometer would be the best as it is more sensitive than the mercury thermometer.
The mercury in the bulb at the bottom of the thermometer expands or contracts depending on the amount of heat (the temperature). The narrow calibrated tube that you read the temperature on acts to amplify this effect. The calibration is usually either in Fahrenheit or Celsius.
If you have an old thermometer that has mercury, then the shaking makes all of the mercury flow to the bottom of the thermometer. Then, you can get a better reading. The current digital ones work differently. Thermometers used for taking people temperatures are a special kind that go up with heat but don't go down with cold. So you have to shake a thermometer before taking your temperature to make the reading go down below your own temperature. Then the thermometer can go up again to read your temperature.
It does not by itself. It must be shaken down. The liquid is mercury, which is very heat-expansive, i.e. it changes its volume noticeably and quickly depending on its temperature. The warmer, the larger the volume. That's why it's used in thermometers. However, thermometers are built so that the mercury does not go down by itself to enable taking precise readings (otherwise, it would fall quickly immediately after the thermometer is removed from the body). So, the thermometer must cool and the contracted but vacuum-stuck mercury must then be shaken down to take another measurement.