Match the following

1. Temperature --- ----------- Kelvin

2. Amount of Substance ----- mole

3. Luminous Intensity --------- Candela

4. Mass ----------------------- kilogram

5. Time ----------------------- Second

1. Kelvin is the primary unit of temperature in SI system. Its symbol is K. The other unit to measure temperature is Celsius , Fahrenheit scale . The freezing point of water is 0⁰C, in Celsius scale but at 0⁰C, water molecules do not come to rest . At -273K all the molecular movement comes to rest. So to avoid negative value we use Kelvin scale :

-273⁰C = 0K

2. SI unit for amount of substance is mole. It has the unit symbol mol. Amount of substance is not its mass , many student got confuses in mol and kilogram. The mass of an substance is the amount of matter contained in it whereas Amount of substance is the number of atom or molecules contained in it.

3. Candela is the SI unit for luminous intensity. Its symbol is cd. A common candle emits light with with a luminous intensity roughly equal to one cd .

4. SI unit of mass is kilogram. Its symbol is kg. We can defined mass as the amount of matter that the body is made up of. It is a characteristic of a body .

5. The SI unit of time is the second. We represent second by symbols.