# Physics – Matter Concept – Important One Liners To Remember

Matter – Solution – Important Points , Concept

1- Early Indian philosophers classified matter in the form of five basic elements – the ‘Panch Tatva’– air, earth, fire, sky and water

2-Kelvin is the SI unit of temperature, 00 C =273.16 K.

For convenience, we take 00 C = 273 K after rounding off the decimal.

To change a temperature on the Kelvin scale to the Celsius scale you have to subtract 273 from the given temperature, and to convert a temperature on the Celsius scale to the Kelvin scale you have to add 273 to the given temperature

3-Atmosphere (atm) is a unit of measuring pressure exerted by a gas. The unit of pressure is Pascal (Pa): 1 atmosphere = 1.01 × 105 Pa.

The pressure of air in atmosphere is called atmospheric pressure.

The atmospheric pressure at sea level is 1 atmosphere, and is taken as the normal atmospheric pressure

4-Sublimation is the change of gaseous state directly to solid state without going through liquid state, and vice versa

5-Latent heat of vaporisation is the heat energy required to change 1 kg of a liquid to gas at atmospheric pressure at its boiling point.

6-Latent heat of fusion is the amount of heat energy required to change 1 kg of solid into liquid at its melting point.

7-Some measurable quantities and their units to remember

Quantity Unit Symbol

Temperature kelvin K

Length metre m

Mass kilogram kg

Weight newton N

Volume cubic metre m3

Density kilogram per cubic metre kg m–3

Pressure pascal Pa

8-Alloys: Alloys are mixtures of two or more metals or a metal and a non-metal and cannot be separated into their components by physical methods

9-A Solution is a homogeneous mixture of two or more substances.

10-At any particular temperature, a solution that has dissolved as much solute as it is capable of dissolving, is said to be a saturated solution.

In other words, when no more solute can be dissolved in a solution at a given temperature, it is called a saturated solution.

The amount of the solute present in the saturated solution at this temperature is called its solubility.

If the amount of solute contained in a solution is less than the saturation level, it is called an unsaturated solution.