Matter in Our Surroundings

Everything in this universe is made up of material which is called Matter.

Things which have mass and occupy space are called matter. In other words matter has mass and volume both.

Early philosophers classified matter in the form of five basic elements, which they called "Panch Tatwa". These are air, earth, fire, sky and water.

In modern days matters are classified into two types on the basis of their Physical and Chemical properties.

Physical Nature of Matter

Matter is made up of Particles

Matter is made of small particles. Which can be seen by some simple activities, such as when salt or sugar is dissolved in water, salt or sugar is disappeared in water, i.e. spread throughout evenly. This happens as the particles of salt or sugar get into spaces between particles of water.

This supports the concept that matter is made of particles.

How Small Are These Particles of Matter?

The particles of matter are very small and are so small that cannot be seen by naked eyes.

When a pinch of dettol or potassium permanganate is put in a glass of water, it colored whole water. This supports that particles are very small.

Characteristics of Particles of Matter

Particles of Matter Have Space between Them

Matter is made of small particles, and there are space between particles of matter.

Sugar or salt gets disappeared when dissolved in water. This happens because particles of sugar or salt evenly distributed between particles of water.

Particles of Matter Are Continuously Moving

Particles of matter are continuously moving as they possess the kinetic energy.

With rise of temperature kinetic energy of particles of matter increases, i.e. particles start moving faster.

Thus, kinetic energy of particles of matter increases with increase in temperature and decrease with decrease in temperature.

When a crystal of potassium permanganate is put in a glass of water, the moving phenomenon of particles of potassium permanganate can be seen easily.

Diffusion

Intermixing of particles of different matter is called diffusion.

Example:

(a) When some sugar of salt is put in a glass of water, after some times particles of sugar or salt get diapered into the particles of water, this happens because of mixing of particles of sugar or salt and water.

(b) When an incense stick is burnt, after some time we get its smell. This happen because particles of smoke coming out of incense stick mixed with particles of air, i.e. diffuse with particles of air.

Particles of Matter Attract Each Other

Particles of matter attract each other. Attraction among particles is because of a force called force of attraction. This attraction keeps them close to each other.

Force of attraction varies in different matter. In some matter force of attraction is very strong while in some matter force of attraction is not so strong.

Intensity of this force of attraction between particles makes a matter hard or soft.

Example:

Water coming out of a tap in continuous stream because particles of water attract each other and keep them closer.

Strong force of attraction between particles in iron makes it harder while less strong force of attraction between particles of soil makes it soft.

States of Matter

There are three states of matter, i.e. matter exists in three states in nature. The states of a matter arise due to variation in the characteristics of the particles of matter. These states are

Solid State

Liquid State

Gaseous State

The Solid State

Solid state of matters has definite shape, definite size, i.e. having distinct boundaries, and fixed volumes.

In other words, state of matters having definite shape, size and volume are called Solid State.

Solids are rigid because they may break under force but it is difficult to change their shape.

Example: a rod of iron, coal, utensils, table, chair, etc.

A piece of coal gets broken when force is applied to it because a piece of coal is in solid state and resists changing its shape.

When a rubber band regain its shape when force applied to stretch it is removed, because it is a solid.

When a lump of sponge is pressed by applying a force, its shape is changed because of expulsion of air bubbles trapped in its pores, by sponge gains its shape after removing the pressure applied over it. This is because it is a solid.

The Liquid State

Matters having definite volume and mass but indefinite shape are called liquid, and such matters are in liquid state.

A liquid gets the shape of container in which it is placed, but in all cases it has same volume and mass.

Example: Water, oil, milk, etc.

The Gaseous State

Matters that do not have definite shape, size or volume are called Gaseous or gas, and this state of matter is called The Gaseous State.

Example: air, oxygen, nitrogen, smoke, etc. All matters are in the form of gas have gaseous state.

Gases take the shape, size and volume of container in which they kept.

Gases are highly compressible as there is much space between their particles, and they can be compressed.

Particles of gases have high kinetic energy and they move fastest compare to liquid and solid. This is the cause that aroma of cooked food reaches to our nostrils even without reaching to the kitchen.

Because of high kinetic energy particles of gas move randomly and exert pressure on the wall of container in which they kept.

CNG (compressed natural gas) is used for cooking and running vehicles. Natural gas is compressed in cylinders and transported to gas stations and homes for further use.

LPG (Liquefied Petroleum Gas) : Petroleum gas is compressed at high pressure because of which spaces between particles get reduced and petroleum gas converted into liquid.

Since, space between particles of gas is largest compare to liquid and solid, thus force of attraction between particles of gases is lowest.

Order of spaces between particles of matters

Gas > Liquid > Solid

Force of attraction between particles of matters

Gas < Liquid < Solid

Can Matter Change Its State?

State of matters can be changed by applying external forces.

Solid can be changed into liquid and liquid can be changed into gas. For example ice is solid of water, water is liquid state and vapour is the gaseous state of water. That means water exists in all the three states of matter.

Ice (solid) ⇒ Water (liquid) ⇒ Vapour (gas)

Factors that affect the State of Matter

Effect of Temperature

Effect of temperature changes the state of matters.

With increase in temperature solid changes into liquid and liquid changes into gas. On the other hand with decrease in temperature a gas changes into liquid and liquid changes into solid state.

Example: When temperature increases ice melts into water and with further increase of temperature water turns into vapour.

When temperature decreases vapour (gas) changes into water (liquid) and on further decrease in temperature water changes into ice (solid state)

On increasing the temperature of solids, the kinetic energy of the particles increases. Due to increase in kinetic energy, the particles start vibrating with greater speed. The energy supplied by heat overcomes the forces of attraction between the particles resulting particles leave their fixed positions and start moving freely. A stage reached when the solid melts and converted to a liquid.

On further increase in temperature, same phenomenon takes place and a liquid changes into gas.

Melting Point: The temperature at which a solid turns into liquid is called the MELTING POINT of that very matter in solid state.

In other words the temperature at which a solid melts to become a liquid at the atmospheric pressure is called its MELTING POINT.

The melting point of a solid is an indication of the strength of the force of attraction between its particles.

The melting point of ice is 273.16 K.

Fusion: The process of melting, that is, change of solid state into liquid state is also known as FUSION.