=> Characteristics of Solid - A solid are a state in which matter is characterized by having definite shape, distinct boundaries, rigidity, incompressibility and fixed volume.
=> Characteristics of Liquid - A liquid is a state in which matter is characterized by having fluidity, low compressibility, no definite boundary or shape but fixed volume.
=> Characteristics of Gases - The gaseous state are characterized by having fluidity, high compressibility, no definite boundary, volume or shape.
=> Melting Point is the temperature at which a solid becomes a liquid at atmospheric pressure.
=> Boiling Point is the temperature at which a liquid changes into its vapour at atmospheric pressure.
=> Latent Heat of Fusion is the amount of heat consumed when 1 kg of a solid changes into liquid at a constant temperature.
=> Latent Heat of Vaporization is the amount of heat consumed when 1 kg of a liquid changes into its vapour at a constant temperature.
=> Evaporation is a surface phenomenon in which a liquid changes into vapour or gas below its boiling point. It results in lowering in temperature (Cooling).
Extrascore Important Notes-cum-Questions
Q.1: Give reasons for the following observation:
The smell of hot sizzling food reaches you several meters away, but to get the smell from cold food you have to go close.
Ans: We smell food as the particles of the aroma of food diffuse in the air of the kitchen and reach us. Diffusion becomes faster if the particles are hot. So the smell of hot sizzling food reaches you several meters away as food particles diffuse faster in air when hot and we smell it in no time whereas cold food particles take a very long time to diffuse and hence, we have to go close to have a smell of it.
Q.2: A diver is able to cut through water in swimming pool. Which property of matter does this observation show?
Ans: The inter-particulate force of attraction in liquid is less than the solid. So, particles of water attract each other but the attraction is not strong enough to prevent the diver to cut through water.
Q.3: What are characteristics of particles of matter?
Ans: Characteristics of particles of matter are as follows -
(i) Particles of matter have space between them.
(ii) Particles of matter are continuously moving and thus, possess kinetic energy.
(iii) Particles of matter can diffuse into one another.
(iv) Particles of matter attract each other. The force of attraction depends on the kind of matter.
(v) The size of a particle of matter can be very small.
Q.4: Why are gases compressible not liquids?
Ans: Inter-particulate distance is more in gas than the liquid. Thus, in gases particles are far apart and there is a lot of empty space between them. So, the gases are compressible whereas in liquids, particles are relatively close to each other and can be brought closer only by applying very high pressure.
=> Characteristics of Liquid - A liquid is a state in which matter is characterized by having fluidity, low compressibility, no definite boundary or shape but fixed volume.
=> Characteristics of Gases - The gaseous state are characterized by having fluidity, high compressibility, no definite boundary, volume or shape.
=> Melting Point is the temperature at which a solid becomes a liquid at atmospheric pressure.
=> Boiling Point is the temperature at which a liquid changes into its vapour at atmospheric pressure.
=> Latent Heat of Fusion is the amount of heat consumed when 1 kg of a solid changes into liquid at a constant temperature.
=> Latent Heat of Vaporization is the amount of heat consumed when 1 kg of a liquid changes into its vapour at a constant temperature.
=> Evaporation is a surface phenomenon in which a liquid changes into vapour or gas below its boiling point. It results in lowering in temperature (Cooling).
Extrascore Important Notes-cum-Questions
Q.1: Give reasons for the following observation:
The smell of hot sizzling food reaches you several meters away, but to get the smell from cold food you have to go close.
Ans: We smell food as the particles of the aroma of food diffuse in the air of the kitchen and reach us. Diffusion becomes faster if the particles are hot. So the smell of hot sizzling food reaches you several meters away as food particles diffuse faster in air when hot and we smell it in no time whereas cold food particles take a very long time to diffuse and hence, we have to go close to have a smell of it.
Q.2: A diver is able to cut through water in swimming pool. Which property of matter does this observation show?
Ans: The inter-particulate force of attraction in liquid is less than the solid. So, particles of water attract each other but the attraction is not strong enough to prevent the diver to cut through water.
Q.3: What are characteristics of particles of matter?
Ans: Characteristics of particles of matter are as follows -
(i) Particles of matter have space between them.
(ii) Particles of matter are continuously moving and thus, possess kinetic energy.
(iii) Particles of matter can diffuse into one another.
(iv) Particles of matter attract each other. The force of attraction depends on the kind of matter.
(v) The size of a particle of matter can be very small.
Q.4: Why are gases compressible not liquids?
Ans: Inter-particulate distance is more in gas than the liquid. Thus, in gases particles are far apart and there is a lot of empty space between them. So, the gases are compressible whereas in liquids, particles are relatively close to each other and can be brought closer only by applying very high pressure.