**What is Temperature**

The degree of hotness or coldness of the body is called the temperature of the body.

A candle flame is hot and is said to be at high temperatures, whilst ice cream is cold and is said to be at reduced/low temperatures.

**Scales of temperature**

A scale is indicated around the thermometer. The warmth of the body in touch with the thermometer can be read on that scale. Three scales of temperatures are in common usage. These are:

- Celsius scale or centigrade scale
- Fahrenheit scale
- Kelvin scale

**Celsius scale or centigrade scale**

Celsius, or centigrade, is a unit and scale of measurement for temperature. It is one of the most widely used temperature units all over the world. This scale is called after the Swedish astronomer Anders Celsius (1701-1744), who produced a comparable temperature scale. The degree of measurement is Celsius (°C).

On the Celsius scale, the interval between upper and lower stationary points is divided into 100 equal parts. The lower fixed point is indicated as 0 °C that is the freezing point of water and the higher point is indicated as 100 °C the boiling point of water.

**Fahrenheit scale**

It is established on a scale suggested in 1724 by physicist Daniel Gabriel Fahrenheit (1686-1736). The degree of measurement is Fahrenheit (°F). On this scale, the interval between the upper and lower points is divided into 180 equal components. Its lower fixed point is indicated as 32 °F and the upper stationary point is indicated as 212 °F.

With this scale, the water freezing point is defined as 32 °F, whilst the water boiling point is defined as 212 °F.

**Kelvin scale**

A Kelvin is a unit of measurement for temperature. It is called after the Glasgow University engineer and physicist William Thomson, 1st Baron Kelvin. In SI units, the unit of temperature is Kelvin (K) and its scale is also named Kelvin scale of temperature. The interval between the upper and lower factors is split into 100 equal parts. Therefore, an alteration in 1°C is equivalent to a change of 1K. The lower fixed point with this scale equates to 273 K and the upper fixed point is at 373 K.

**Absolute Zero**

The zero on the Kelvin (K) scale is known as the absolute zero and is equivalent to – 273 °C. Absolute zero is the possible coldest temperature. Absolute zero describes a condition where all of the energy of some system is extracted. It is the ideal temperature where gases can become liquified. But this temperature is impossible to reach.

**Conversion Of temperature into different scales**

**From Celsius to Kelvin**

This can be obtained by using this formula.

**Example:**

What will be the temperature in Kelvin when it is 30 °C on the Celsius scale?

C = 30°

By putting the value of C

**From Kelvin to Celsius**

This can be obtained by subtracting 273 from the given temperature.

Example:

Change 300K on Kelvin scale into Celsius scale

C = 27°

**From Celsius to Fahrenheit**

Example:

##### Convert 50°C to Fahrenheit scale

**From Fahrenheit to Celsius**

Convert 100 °F into Celsius