Class 9, Matter in Our Surroundings | NCERT Science Chemistry - CBSE Guide, Notes and Guess Questions

 

Matter in Our Surroundings

CBSE Class 9, NCERT Science Chemistry

CBSE Guide – NCERT Questions Bank - CBSE Guess Questions with Solutions

Important Definitions (Points)
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 is characterized by having fluidity, high compressibility, no definite boundary, volume or shape.
Melting Point
It is the temperature at which a solid becomes a liquid at atmospheric pressure.
Boiling Point
It is the temperature at which a liquid changes into its vapour at atmospheric pressure.     
Latent Heat of Fusion
LHF is the amount of heat consumed when 1 kg of a solid changes into liquid at a constant temperature.
Latent Heat of Vaporization
LHV is the amount of heat consumed when 1 kg of a liquid changes into its vapour at a constant temperature.  
Evaporation
It is a surface phenomenon in which a liquid changes into vapour or gas below its boiling point. It results in lowering in temperature (Cooling).

Matter In Our Surroundings - NCERT (CBSE) Hot Questions

Question.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.  
Question.2: A diver is able to cut through water in swimming pool. Which property of matter does this observation show?
Question.3: What are characteristics of particles of matter?
Question.4: Why are gases compressible not liquids?
Question.5: Give reasons
(a) A gas fills completely the vessel in which it is kept.
(b) A gas exerts pressure on the walls of the container.
(c) A wooden table should be called solid.
(d) We can easily move our hand in air but to do the same through a solid block of wood we need a karate expert.
Question.6: Liquids generally have lower density as compared to solids. But you must have observed that ice floats on water. Find out why?
Question.7: Differentiate between the properties of three states of matter.
Question.8: For any substance, why does temperature remain constant during the change of state?
Question.9: Suggest a method to liquefy atmospheric gases.
Question.10: Why does a desert cooler cool better on a hot dry day?
Question.11: How does the water kept in an earthen pot (matka) become cool during summer?
Question.12: Why does our palm feel cold when we put some acetone or petrol or perfume on it?
Question.13: Why are we able to sip hot tea or milk faster from a saucer rather than a cup?
Question.14: What type of clothes should we wear in summer?
Question.15: What is meant by saying that the latent heat of vaporization of water is 22.5 x 105 J/Kg?
Question.14: What is meant by saying that the latent heat of fusion of ice is 3.34 x 105 J/Kg?
CBSE Class IX, NCERT Science (Chemistry) - Matter in Our Surroundings - Also Study
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·        CBSE Class 9, Matter in Our Surroundings - Answers of NCERT Science Chapter 1 Exercise Questions [READ]

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