Chair, air, almonds, cold drink are matter.

It is the property of matter that increasing the temperature, the particles of matter spread very faster. Thus the smell of hot food spread faster than cool food.

This observation shows that the particles of matter have space between them.

The characteristics of the particles of matter are the following.

(i) Particles of matter have space between them.

(ii) Particles of matter are continuously moving.

(iii) Particles of matter attract each other.

air, exhaust from chimneys, cotton, water, honey, chalk, iron

Rigidity - Rigidity is the property of solid. It means unbending (hardness). It cannot be changed its shape.                         

Compressibility – The particles of matter have space between them. So the gases have more compressibility.

Fluidity – it is a property of matter. In which matters spread on the surface.

Filling a gas container – The state of matter which has a space between particles and property of compressibility that fills a gas container completely.

Shape – Shape is a physical view of matter in which they acquire their size.

Kinetic energy and density – having kinetic energy the states of matter in increasing order such as solid, liquid and gas has more kinetic energy. But in density solid is most than other and gas is lowest than all.

Gases has high compressibility and low attraction force between particles, When they kept due to high compressibility and low attraction force particles spread all arround in the vessels. So gases fill completely the vessels in which it is kept.

Gases show the property of diffusing very fast into other gases. In the gaseous state, the particles move about randomly at high speed. Due to this random movement, the particles hit each other and also the walls of the container.

A wooden table has the properties of a definite shape, fixed volume and intermolecular space is strong, so it should be called a solid.

: The intermolecular space between the particles of air is more and therefore intermolecular force is too weak so we can easily move our hands in air. Whereas intermolecular space in solid is very strong so we need a karate expert. 

The particles of ice far away from each other while water is stronger due to hydrogen bonding. So the volume of ice is more and density is less. This makes ice to float on water.

{ changing in Celsius scale 273 is subtracted form given Kelvin value}

273 k = 0 ०C

300 k – 273 = 27 ०C               

Hence 300k = 27 ०C

573 k – 273 = 300 ०C

Hence 573k = 300 ०C

Water is liquid at 25 ^०C.

Water is solid at 0 ^०C.

Water is gas at 100 ^०C.

The temperature remain constant during the change of state because the heat supply is used up in changing the state by overcoming the force of attraction between the particles. In common words, all given temperature is absorbed by particles during changing the state of matter so over all the temperature remains constant. This is also called latent heat.

On a hot day temperature is higher. This temperature increases the rate of evaporation cause better cooling by desert cooler. During the evaporation particles absorbed heat from surround and used in evaporating the cooler water and increases the rate of evaporation. This is the reason desert cooler cools better in a hot dry day.

An earthen pot (matka) has many fine pores in it through which evaporation takes place and it absorbs heat from outside of Matka this causes increasing rate of evaporation resulting in cooling water.

When we put some acetone or petrol or perfume on our palm it spread over palm in a large area. We know evaporation increases due to increasing surface area. It gains energy and gets evaporated cause cooling.

The surface area of saucer is more than the surface area of cup. The rate of evaporation is faster in saucer and therefore, cooling is also faster than cup.

: We should wear cotton clothes during summer season becuase we sweat a lot more in the summer season. Cotton material is very powerful water absorber that helps in the absorption of perspiration this cause increase in surface area for evaporation of perspiration as a result incease the rate of evaporation. As perspiration escapes from our bodies, our bodies lose heat and causing feeling cool. 

Naphthalene is a sublimely agent which get sublimated and change directly from solid to gas. Hence the Naphthalene balls disappear with time without leaving any solid.

It is due to diffusion. The particles of perfume move at random motion in all directions and mix with air molecules so We can get the smell of perfume sitting several metres away.

The room temperature is less than the boiling point of water and more than the temperature at this solidifies. Therefore water is liquid at room temperature.

The room temperature is not more than the its melting point. While melting point of iron is much higher. So an iron Almirah is a solid at room temperature.

Water at 273 k takes heat during increasing in temperature but do not change it state but ice at same temperature takes heat and changes its state due to this ice is more effective in cooling than water at the same temperature.

Steam , it boils at 373 K and has more quantity of heat due to its gaseous form it has more compression than the liquid form of water.