Why is only mercury is used in a thermometer?

Answer 1

Because mercury is the only liquid metal and liquids expand more than solids on heating.

AnswerMercury is one of the few elemental substances that is liquid at room temperature. Like all substances, mercury linearly expands as temperature increases. Coupling these two properties, a thermometer is formed.

By confining the mercury to a container of known dimensions, one can determine the ambient temperature based on how much volume a constant mass of mercury occupies. Because mercury expands very little relative to daily temperature changes, the cross section of thermometers must be small enough to accentuate this change in volume.

• It doesn't wet glass
• It doesn't vaporize easily ( boils at 360 degree Celsius )
• It is opaque and easily seen
• It is a better conductor of heat and responds more rapidly to changes in temperature

1. Mercury does not wet glass, this makes the threadmove up and down without breaking.

2. It is a shining metal and easily seen.

3. It is a liquid up to 300 deg C.
Low freezing point and high boiling point.
Mercury is a metal, and so it has a fairly high temperature expansion coefficient. It is also silver, so it is quite good visible in a glass pipe, and to top it off, it's a liquid, so it can flow upward in the measurement pipe while the mercury in the reservoir expands.

Answer

Mercury, like alcohol is reactive to heat and expands when heated and contracts when cooled. This causes the Mercury to move up and down the tube.

ANSWER

Mercury or alchohol
Mercury is the only metal that is a liquid at room temperature, and is therefore the only metal that can be considered for a thermometer.

Metals in general expand more than most other materials when heated, which makes it easier to see the differences with the naked eye.

These two characteristics combined is the reason why mercury is suitable for thermometers.

Answer 2

It's got quite a high index of increasing volume proportional to increasing temperature, which makes it useful. Nowadays, due to the potential harmful effects of Mercury on human organic circuitry, synthetic chemicals with duplicated properties are used.

Answer 3

Thermometers used to have mercury in them because it is very temperature reactive and a liquid across most temperatures measured in everyday life. However, this practice has been discontinued due to the health risks associated with contact with mercury from broken thermometers; most analog thermometers today use colored ethanol as the measuring fluid.

Answer 4

Mercury is not the only liquid used in thermometers. Alcohol is used in thermometers intended for measuring very low temperatures (e.g. on Antarctic surveys) because its freezing point is lower than Mercury's.There are also many other things used for the manufacture of thermometers.

See link below.

Also it is now illegal to sell thermometers containing mercury in Europe, due to the environmental damaged that is caused when they break or are disposed of.

Answer 5

mercury is unique in that it is a liquid at room temperature. this property allows it to expand as the temperature rises and contract as the temperature cools much more freely than metals in a solid state.

Answer 6

it has high specific heat