# Chapter 1 : Matter in Our Surroundings Questions and Answers Science Class 9

NCERT Solutions for Class 9 Science Chapter 1 Matter in Our Surroundings – There are all the NCERT results for Class 9 Science Chapter 1. This post contains Questions, Answers, images, step by step explanations of the complete Chapter 1 named Matter in Our Surroundings of Science tutored in class 9.

## NCERT Solutions for Class 9 Science Chapter 1 Matter in Our Surroundings Questions and Answers

Page-3

Q1. Which of the following are matter :

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

Solution: Anything that occupies space and has mass is called matter. Matter can exist in three physical states – solid, liquid, and gaseous. Chair and almonds are forms of matter in a solid state. A cold drink is a liquid state of matter. Air and the smell of perfume are gaseous states of matter.

Q2. 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.

Solution: Solids diffuse at a very slow rate. But, if the temperature of the solid is increased, then the rate of diffusion of the solid particles into the air increases. This is due to an increase in the kinetic energy of solid particles. Hence, the smell of hot sizzling food reaches us even at a distance, but to get the smell from cold food we have to go close.

Q3. A diver is able to cut through water in a swimming pool. Which property of matter does this observation show?

Solution: The ability of a diver to cut through water in a swimming pool shows that matter is made up of particles.

Q4. What are the characteristics of particles of matter?

Solution: The characteristics of particles of matter are:

1. Particles of matter have spaces between them.
2. Particles of matter are continuously moving.
3. Particles of matter attract each other.

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Q1. 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 a chimney, honey, water, chalk, cotton, and iron.

Solution: The given substances in the increasing order of their densities can be represented as:

Air < Exhaust from chimney < Cotton < Water < Honey < Chalk < Iron

Q2. A) Tabulate the differences in the characteristics of states of matter.

Solution: (A) The differences in the characteristics of states of matter are given in the following table:

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

(B) Rigidity: It can be expressed as the tendency of matter to resist a change in shape.

Compressibility: is the ability to be reduced to a lower volume when force is applied.

Fluidity: The ability to flow.

By filling a gas container: We mean the attainment of the shape of the container by gas.

Shape: Defines as a definite boundary.

Kinetic Energy: The energy possessed by a particle due to its motion.

Density: Mass per Unit Volume.

Q3. Give reasons:

1. A gas fills completely the vessel in which it is kept.
2. A gas exerts pressure on the walls of the container.
3. A wooden table should be called a solid.
4. We can easily move our hand in air, but to do the same through a solid block of wood, we need a karate expert.

Solution: a) There is little attraction between particles of gas. Thus, gas particles move freely in all directions. Therefore, gas completely fills the vessel in which it is kept.

b) Particles of gas move randomly in all directions at high speed. As a result, the particles hit each other and also hit the walls of the container with a force. Therefore, gas exerts pressure on the walls of the container.

c) A wooden table has a definite shape and volume. It is very rigid and cannot be compressed i.e., it has the characteristics of a solid.  Hence, a wooden table should be called a solid.

d) Particles of the air have large spaces between them. On the other hand, wood has little space between its particles. Also, it is rigid. For this reason, we can easily move our hands in air, but to do the same through a solid block of wood, we need a karate expert.

Q4. Liquids generally have a lower density as compared to solids. But you must have observed that ice floats on water. Find out why.

Solution: The mass per unit volume of a  substance is called density  (density  =  mass/volume).

Though ice is solid, it has a large number of empty spaces between its particles. These spaces are larger as compared to the spaces present between the particles of water. Thus, the volume of ice is greater than that of water. Hence, the density of ice is less than that of water.  A substance with a lower density than water can float on water. Therefore, ice floats on water.

Page-9

Q1. Convert the following temperature to Celsius scale:

1. 300K
2. 573K

Solution: (a) 300K = (300 − 273) °C = 27°C

(b) 573 K = (573 − 273) °C = 300 °C

Q2. What is the physical state of water at:

1. 250°C
2. 100°C

Solution:

(a) Water at 250°C exists in a gaseous state.

(b) At 100°C, water can exist in both liquid and gaseous forms.  At this

temperature, after getting the heat equal to the latent heat of vaporization,

water starts changing from a liquid state to a gaseous state.

Q3. For any substance, why does the temperature remain constant during the change of state?

Solution: During a change of state, the temperature remains constant. This is because all the heat supplied to increase the temperature is utilised (as latent heat) in changing the state by overcoming the forces of attraction between the particles. Therefore, this heat does not contribute in increasing the temperature of the substance.

Q4. Suggest a method to liquefy atmospheric gases.

Solution: By applying pressure and reducing the temperature, atmospheric gases can be liquefied.

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Q1. Why does a desert cooler cool better on a hot dry day?

Solution: In a desert cooler, the water inside it is made to evaporate. This leads to the absorption of energy from the surroundings, thereby cooling the surroundings. Again, we know that evaporation depends on the amount of water vapour present in the air (humidity). If the amount of water vapour present in the air is less, then evaporation is more. On a hot dry day, the amount of water vapour present in the air is less. Thus, water present inside the desert cooler evaporates more, thereby cooling the surroundings more. That is why a desert cooler cools better on a hot dry day.

Q2. How does water kept in an earthen pot (matka) become cool during summers?

Solution: There are some pores in an earthen pot through which the liquid inside the pot evaporates. This evaporation makes the water inside the pot cool.  In this way, water kept in an earthen pot becomes cool during summers.

Q3. Why does our palm feel cold when we put some acetone or petrol or perfume on it?

Solution: When we put some acetone or petrol or perfume on our palm, it evaporates. During evaporation, particles of the liquid absorb energy from the surrounding or the surface of the palm to compensate for the loss of energy, making the surroundings cool.  Hence, our palm feels cold when we put some acetone or petrol or perfume on it.

Q4. Why are we able to sip hot tea or milk faster from a saucer than a cup?

Solution: A liquid has a larger surface area in a saucer than in a cup. Thus, it evaporates faster and cools faster in a saucer than in a cup. For this reason, we are able to sip hot tea or milk faster from a saucer than from a cup.

Q5. What type of clothes should we wear in summer?

Solution: We should wear cotton clothes in summer. During summers, we sweat more. On the other hand, cotton is a good absorber of water. Thus, it absorbs sweat from our body and exposes the liquid to the atmosphere, making evaporation faster. During this evaporation, particles on the surface of the liquid gain energy from our body surface, making the body cool.

Exercise

Q1. Convert the following temperatures into the Celsius scale.

1. 300K
2. 573K

Solution: a) 300 K = 300 – 273 = 270 C

b) 573 K = 573 – 273 = 3000 C

Q2. Convert the following temperatures into the Kelvin scale.

a) 250 C

b) 3730 C

Solution: a) 250 C = 25 + 273 = 298 K

b) 3730 C = 373 + 273 = 646 K

Q3. Give reasons for the following observations:

a) Naphthalene balls disappear with time without leaving any solid.

b) We can get the smell of perfume sitting several meters away.

Solution: a) Naphthalene shows the property of sublimation. Evaporation of naphthalene takes place easily and so it disappears over the course of time without leaving a solid.

b) Perfumes vaporize very fast and their vapours diffuse into the air easily. That is why we can smell perfume sitting several meters away.

Q4. Arrange the following in increasing order of forces of attraction between the particles – water, sugar, oxygen.

Solution: Oxygen < Water < Sugar.

Q5. What is the physical state of water at —

a) 25 °C

b) 0 °C

c) 100 °C

Solution: a) Liquid

b) Solid and Liquid

c) Liquid and Vapours

Q6: Give two reasons to justify:

a) Water at room temperature is a liquid.

b) An iron Almirah is a solid at room temperature.

Solution: a) Water at room temperature is a liquid because it has fluidity and has definite volume but no definite shape.

b) An iron Almirah is a solid at room temperature because it is rigid and has a definite shape.

Q7. Why is ice at 273 K more effective in cooling than water at the same temperature?

Solution: Ice at 273 K is less energetic than water. It is because of the difference in the latent heat of fusion which is present in water at the same temperature in the form of extra energy.

Q8. What produces more severe burns, boiling water or steam?

Solution: Steam produces more severe burns than boiling water. This is because steam has more energy than boiling water, present in it in the form of latent heat of vaporization.

Q9. Name A, B, C, D, E and F in the following diagram showing the change in its state:

Solution:

A →Melting

B →Boiling

C →Condensation

D →Solidification

E →Sublimation

F →Sublimation

Matter in Our Surroundings MCQ Class 9

FAQ about NCERT Solutions for Class 9 Science Chapter 1 “Matter in Our Surroundings” Questions and Answers:

1. What are NCERT Solutions for Class 9 Science Chapter 1 “Matter in Our Surroundings”?

• NCERT Solutions for Class 9 Science Chapter 1 “Matter in Our Surroundings” are a set of comprehensive answers and explanations to the questions and exercises provided in the NCERT textbook for this chapter. These solutions help students understand the concepts related to matter, its states, and various properties. They are designed to assist students in preparing for their exams and gaining a better grasp of the subject matter.

2. How can NCERT Solutions for Class 9 Science Chapter 1 benefit students?

• NCERT Solutions for Class 9 Science Chapter 1 “Matter in Our Surroundings” can benefit students in several ways. Firstly, they provide detailed explanations for each question and exercise in the textbook, helping students comprehend complex concepts. Secondly, these solutions serve as a valuable resource for exam preparation, allowing students to practice and assess their understanding. Additionally, they can be used for self-study and as a reference for homework, ensuring that students have a strong foundation in this fundamental scientific topic.

3. Are NCERT Solutions for Class 9 Science Chapter 1 freely available?

• Yes, NCERT Solutions for Class 9 Science Chapter 1 “Matter in Our Surroundings” are often available for free on various educational websites and platforms. The National Council of Educational Research and Training (NCERT) provides these solutions as part of its mission to make quality educational materials accessible to all students. Additionally, teachers and educational institutions may also offer these solutions to their students. Students can access them online or download them for offline use to support their learning and exam preparation.

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Matter in Our Surroundings Notes

NCERT Solutions for Class 9 Science

### 21 thoughts on “Chapter 1 : Matter in Our Surroundings Questions and Answers Science Class 9”

1. Good

2. Ans. State of matter solid liquid gas

• right

3. ans2. The boiling point of water 100
degrees celsius
ans3.early indian philosophers classifieds matter in the form of basic elements the “panch tatva” : air ,FIR ,Sky, water and earth

• good

4. Ok

5. Bhai pubg lite keshav yani mera h

6. Answer :1)There are three types of state of matter are :
(1)Solid.
(2)Liquid.
(3)Gas.
Answer :2)The boiling point of water is 100 degree celsius .
Answer :3)Early Indian philosphers classified matter into five basic elements,called Panch Tatva

8. Ans1.there are three state of matter
1.solid
2.liquid
3.gas
* SOLID= they have fixed shape
they can’t break easily
*LIQUID= they can not have fixed shape
they can be easily divided into two parts
*GAS= they have the property of diffusion
they are highly compressible

Ans2. the boiling point of water is 100 degree Celsius.

Ans3. Early Indian philosoper classifed the matter into five elements is called ‘Panch – tatva.
*Sky
*Air
*water
*land
*fire

9. Nice

10. Q1.How will we seprate?
1.oil from water
2.Anmonium chloride from salt
3.Nitrogen from gas
4.pigments of Flower

Q2. Write Note on the following.
1.Pure substance
2.Saturated solution
3.Chromatography

• ok please give me 24 hour

12. Good

13. Ans1). There are three state of matter-
1)Solid
*they have fixed shape.
*they can’t break easily.
2)Liquid
*they can’t have fixed shape, example : water filled in any container they take a container shape .
*they can be easily divided into two part.
3)Air
*they have the property of diffusion.
*they are highly compresible . Ans2). The boiling point of water is 100 degree celsius .
Ans3). Early Indian philosphers classified the matter into five elements is called Panch-Tatva.