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NCERT solutions Science Class 9 chapter 1 Matter in Our Surroundings

Chapters

NCERT Science Class 9

Science Textbook for Class 9

Chapter 1 - Matter in Our Surroundings

Page 3

Which of the following are matter?

Chair, air, love, smell, hate, almonds, thought, cold, cold drink, smell of perfume.

Q 1 | Page 3

Give reasons for the following observation:

The smell of hot sizzling food reaches you several metres away, but to get the smell from cold food you have to go close.

Q 2 | Page 3

A diver is able to cut through water in a swimming pool. Which property of matter does this observation show?

Q 3 | Page 3

What are the characteristics of particles of matter?

Q 4 | Page 3

Page 6

The mass per unit volume of a substance is called density (density = mass/volume). Arrange the following in order of increasing density − air, exhaust from chimney, honey, water, chalk, cotton, and iron.

Q 1 | Page 6

Tabulate the differences in the characteristics of states of matter.

Q 2.1 | Page 6

Comment upon the following:- rigidity, compressibility, fluidity, filling a gas container, shape, kinetic energy, and density.

Q 2.2 | Page 6

Give reasons:- A gas fills completely the vessel in which it is kept.

Q 3.1 | Page 6

Give reasons:-

A gas exerts pressure on the walls of the container.

Q 3.2 | Page 6

Give reasons:- We can easily move our hand in air, but to do the same through a solid block of wood, we need a karate expert.

Q 3.3 | Page 6

Give reasons:- A wooden table should be called a solid.

Q 3.4 | Page 6

Liquids generally have lower density as compared to solids. But you must have observed that ice floats on water. Find out why.

Q 4 | Page 6

Page 9

Convert the following temperature to Celsius scale:- 300 K

Q 1.1 | Page 9

Convert the following temperature to Celsius scale:-573 K

Q 1.2 | Page 9

What is the physical state of water at 250°C.

Q 2.1 | Page 9

What is the physical state of water at 100°C.

Q 2.2 | Page 9

For any substance, why does the temperature remain constant during the change of state?

Q 3 | Page 9

Suggest a method to liquefy atmospheric gases.

Q 4 | Page 9

Page 10

Why does a desert cooler cool better on a hot dry day?

Q 1 | Page 10

How does water kept in an earthen pot (matka) become cool during summers?

Q 2 | Page 10

Why does our palm feel cold when we put some acetone or petrol or perfume on it?

Q 3 | Page 10

Why are we able to sip hot tea or milk faster from a saucer than a cup?

Q 4 | Page 10

What type of clothes should we wear in summers?

Q 5 | Page 10

Page 12

Convert the following temperatures to the celsius scale.293 K

Q 1.1 | Page 12

Convert the following temperatures to the celsius scale. 470 K

Q 1.2 | Page 12

Convert the following temperatures to Kelvin scale.25°C

Q 2.1 | Page 12

Convert the following temperatures to Kelvin scale.373°C

Q 2.2 | Page 12

Give reason for the following observation. Naphthalene balls disappear with time without leaving any solid.

Q 3.1 | Page 12

Give reason for the following observation. We can get the smell of perfume sitting several metres away.

Q 3.2 | Page 12

Arrange the following substances in increasing order of forces of attraction between particles - water, sugar, oxygen.

Q 4 | Page 12

What is the physical state of water at 25°C.

Q 5.1 | Page 12

What is the physical state of water at 0°C.

Q 5.2 | Page 12

Give two reasons to justify water at room temperature is a liquid.

Q 6.1 | Page 12

Give two reasons to justify an iron almirah is a solid at room temperature.

Q 6.2 | Page 12

Why is ice at 273 K more effective in cooling than water at the same temperature?

Q 7 | Page 12

What produces more severe burns, boiling water or steam?

Q 8 | Page 12

Name A, B, C, D, E and F in the following diagram showing change in its state.

Q 9 | Page 12

NCERT Science Class 9

Science Textbook for Class 9
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