Pick a type of thermometer. How does it work? Suppose you used water in a thermometer instead of mercury, why might this be a problem at 4 degrees Fahrenheit?
The water would be ice, expand, and break the glass
If you have a thermometer with liquid in it that expands as it warms (for example Mercury), it fills more of the thermometer tube as it expands. Ice would be unfortunate and if the thermometer were glass with water in it it would probably break as the water froze around 32 degrees F.
One type of thermometer that could be considered is a liquid-in-glass thermometer. This is a common type of thermometer used in households and laboratories.
The workings of a liquid-in-glass thermometer are simple. It consists of a narrow glass tube filled with a liquid, typically mercury or alcohol. As temperature changes, the liquid expands or contracts, causing it to rise or fall within the tube. The scale on the thermometer allows us to read the temperature.
Now, let's consider using water instead of mercury in the thermometer at 4 degrees Fahrenheit. At this temperature, water begins to freeze and turns into ice. Unlike most substances, water expands as it freezes. If water is used in the thermometer and it reaches 4 degrees Fahrenheit, the water inside will start to freeze and expand. This expansion can cause the glass tube to crack or break, rendering the thermometer useless.
This is one of the reasons why water is not commonly used as a filling liquid in thermometers. Mercury is preferred due to its low freezing point, which is around -38.83 degrees Celsius (-37.89 degrees Fahrenheit). It remains in a liquid state within the thermometer over a wide range of temperatures, making it suitable for various applications.