Red and blue coloured alcohols are the most common in modern times, although Mercury was used for a long time before people figured out how toxic it was.
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iodine and mercury
Alcohol is not the liquid in a candy thermometer. It is a proprietary mixture of chemicals. it is poisonous. Some of them now contain substances such as toluene.
Alcohol is not the liquid in a candy thermometer. It is a proprietary mixture of chemicals. it is poisonous. Some of them now contain substances such as toluene.
use a thermometer.We can feel how hot or cold something is. However, sometimes things are just too hot or cold for us to feel safely. At other times we need to know exactly how hot or cold something is. When we need to measure temperature correctly we need to use an instrument called a thermometer. This measures temperature in degrees Celsius [sometimes called centigrade] or degrees Fahrenheit. There are different types of thermometers for different situations. A medical thermometer, for example, needs to be very accurate. It measures in fractions of degrees. When we are ill, even tiny changes in temperature are important. Some thermometers use a liquid that moves up a very fine glass tube. Most room thermometers, and outdoor thermometers are like this. The liquid is either mercury [ which is poisonous] or coloured alcohol. As liquids get warmer they expand [get bigger], and move up the tube. Water expands too, but not as much as alcohol and mercury. Thermometers that might be used by small children are not made of glass. They use a digital display which lights up the temperature. Inside the displays are chemicals that change colour according to the temperature.
Mercury, like most substances, expands when it gets hotter and contracts when it gets colder. A mercury thermometer is designed so that the volume of the mercury can be accurately observed, as the mercury rises or falls in a marked column.
Celsius, Fahrenheit, and Kelvin.
The cold reduces the temperature in the liquid inside the thermometer bulb. Most substances contract when their temperature drops so the liquid in the bulb occupies less space. this causes the column of liquid outside the bulb to become smaller.
Thermometer
a thermometer
What kind of thermometer you use to measure the body temperature
a thermometer thermometer a thermometer