Page 52 - Science Class 6 Times Publication

Temperature is dened as the degree of hotness or coldness of a
substance.
Its SI unit is Kelvin (K). It is also measured in degree Celsius (°C) and
degree Fahrenheit (°F). It is measured by thermometer.

The substances having high temperature are hotter than the substances
having low temperature. The substances with high temperature have the
molecules vibrating with high speed whereas the substances with low
temperature have the molecules vibrating with low speed.

Thus, the temperature shows the degree of speed of vibration of molecules
of a substance too.

Differences between heat and temperature

Heat Temperature

1. It is a form of energy which gives the 1. It is the degree of hotness or coldness

sensation of warmth. of a substance.
2. It is measured in the units such as 2. It is measured in Kelvin, degree
Joule or Calorie. Celsius or degree Fahrenheit.
3. It is measured by calorimeter. 3. It is measured by thermometer.

Thermometer

It is a device which is used to measure the temperature of a substance.
It works on the principle that “liquid expands on heating and contracts
on cooling”. It contains a liquid called thermometric liquid. Mercury
or alcohol is used as thermometric liquid in a thermometer.

Thermometer is of two types.

a. Laboratory thermometer
b. Clinical thermometer

Laboratory thermometer

It is a thermometer which is used to measure temperature of substances.
Generally, it is used in laboratory. It generally uses alcohol as the
thermometric substance. It measures the temperature from -10°C to
110°C.

Times' Crucial Science and Environment 48 Book 6