Question

Why is mercury used in thermometers?

Answer 1

Hint: A mercury thermometer consists of a glass tube filled with mercury and marked with a standard temperature scale. The mercury expands and contracts in response to temperature variations, allowing the temperature to be read from the scale. It also has a high boiling point, making it ideal for determining higher temperatures.

Complete step by step answer:
At normal temperature, most metals are solids and good heat conductors. Mercury is a good heat conductor. Because of its high coefficient of expansion, it is utilised in thermometers. Its stage accurately and as quickly as possible indicates the temperature. At ambient temperature, mercury is the only one in a liquid state. It does not expand when it freezes, thus it does not shatter the thermometer's glass tube.
Causes of Mercury used in Thermometer –
Mercury thermometers can be used to determine the temperature of the body, liquid, or vapour. Households, laboratory investigations, and industrial applications all employ these thermometers. Mercury is dangerous, thus it's being phased out practically everywhere.
Mercury thermometers are used in a variety of applications, including power plants and pipes, chemical tanks, heating and cooling equipment, canneries, ships, and paint kettles, among others.
Mercury is utilised in thermometers because of its many benefits. The advantages of using mercury in a thermometer are as follows:
1. Mercury is a good heat conductor. As a result, the mercury level indicates the temperature as soon and accurately as feasible.
2. Mercury can be purchased in its purest form.
3. Because mercury is transparent and brilliant, the movement of mercury inside the capillary tube may be seen clearly.
4. Mercury does not adhere to the surface of the glass. As a result, it can freely move inside the capillary glass tube.
5. Mercury expands uniformly across the entire temperature range. As a result, the temperature is accurate.
6. Mercury has a substantially higher conductivity and expands quickly, indicating a rapid temperature change.
7. With the exception of extremely high temperatures, the increase in mercury is constant or linear with increases in heat.

Note: Mercury thermometers are inexpensive, long-lasting, and accurate. They do, however, pose a number of safety and environmental risks. As safety and environmental concerns demand stronger rules on the removal of mercury-containing items, their usage is rapidly being restricted to industrial and technical uses. Mercury poisoning is especially dangerous to foetuses, babies, and children.