KSEEB Solutions for Class 9 Science Chapter 1 Matter in Our Surroundings

Students can Download Science Chapter 1 Matter in Our Surroundings Questions and Answers, Notes Pdf, KSEEB Solutions for Class 9 Science helps you to revise the complete Karnataka State Board Syllabus and to clear all their doubts, score well in final exams.

Karnataka State Syllabus Class 9 Science Chapter 1 Matter in Our Surroundings

KSEEB Class 9 Science Matter in Our Surroundings Intext Questions and Answers

Question 1.
Which of the following is matter? Chain, air, love, smell, hate almonds, thought, cold, cold-drink, the smell of perfume.
Answer :
Chair, air, almonds, cold drink.

Question 2.
Give reasons for the following observation. The smell of hot sizzling food reaches you several matters away but to get the smell from cold food you have to go close.
Answer :
The rate of evaporation depends upon temperature.

Question 3.
A diver is able to cut through water in a swimming pool. Which property of matter does this observation show?
Answer :
Force of attraction between the molecules is less.

Question 4.
What are the characteristics of the particles of matter?
Answer :

Solid	Liquid	Gases
1. Closely packed 2. More force of attraction	Loosely packed Less force of attraction	Very loosely packed Very less force of attraction

Question 5.
The mass per unit volume of a substance is called density.
Answer :
(density = mass / volume)
Arrange the following in order of increasing density.
Air, exhaust from the chimney, honey, water, chalk, cotton, and iron.
Exhaust from chimney
Air – Water – Honey
Chalk – Cotton – Iron

Question 6.
(a) Tabulate the differences in characteristics of states of matter.
Answer :

Solid	Liquid	Gases
1. Definite in shape	Gets the shape of the container	Gets the shape of the container in which it is filled.
2. More density	Less density	Very less density.
3. Force of attraction between the molecules is more.	Force of attraction between the molecules is less.	Force of attraction between the molecules is very- less.

(b) Comment upon the following:

Rigidity : Strength to retain shape
Compatibility : More in gases (intermolecular forces lens)
Fluidity : Liquids possess due to less molecular attraction
Filling a gas container : No shape (random movement)
Shape : Solid, molecules have a definite shape
Kinetic energy : Gases posses due to more space
Density : More for solids

Question 7.
Give reasons.
(a) A gas fills completely the vessel in which it is kept.
Answer :
No definite shape and lesser molecular force of attraction.

(b) A gas exerts pressure on the walls of the container.
Answer :
The random movement of molecules and more distance between them.

(d) We can easily move our hand in the air but to do the same through a solid block of wood we need a karate expert.
Answer :
Air molecules are less force of attraction. Whereas in solid block molecules are very rigid, high density and compres duty to avoid damage. We need to know the technique to break the wood, through proper energetic force.

Question 8.
Liquids generally have lower density as compared to solids but you must have observed that ice floats on water find out. Why?
Answer :
The relative density of ice is lower than the density of water, the buoyant force of water makes the ice to float.

Question 9.
Convert the following temperature to Celsius scale.
(a) 300 K
Answer :
C° = K°- 273
= 300 – 273
= 27°C

(b) 573 K (C° = K°-273)
Answer :
C° = 573 – 273
= 300°C

Question 10.
What is the physical state of water at (a) 25°C (b) 100°C
Answer :
(a) 25°C = Liquid
(b) 100°C = Liquids to gases

Question 11.
For any substance, why does the temperature remain constant during the change of state?
Answer :
Latent heat of a substance.

Question 12.
Suggest a method to liquefy atmospheric gases.
Answer :
Condensation

Question 13.
Why does a desert cooler cool better on a hot dry day?
Answer :
Water evaporates to hot dry weather, evaporation causes cooling.

Question 14.
How does the water keep in an earthen pot (matka) become cool during summer?
Answer :
Latent heat (pores of pot allow the water to evaporate) and makes cool.

Question 15.
Why does our palm feel cold when we put some acetone or petrol or perfume on it?
Answer :
Latent heat *of vapourization (all are having volatile character)

Question 16.
Why are we able to sip hot tea or ‘ milk faster from saucer rather than a cup?
Answer :
The area of vaporization is more in a saucer.

Question 17.
What type of clothes should we wear in summer?
Answer :
Cotton clothes

KSEEB Class 9 Science Matter in Our Surroundings Textbook Exercise Questions and Answers

Question 1.
Convert the following temperature to the celsium scale, (a) 293 K (b) 470 K
Answer :
(a) 293 K
293 – 273 = 20°C
(b) 470 K
470 – 273 = 197°C

Question 2.
Convert the following temperatures to the Kelvin scale, (a) 25°C, (b) 373°C
Answer :
(a) 25°C = 25 + 273 = 298 K
(b) 373°C = 373 + 273 = 646 K

Question 3.
Give the reason for the following observations.

(a) Naphthalene balls disappear with time without leaving any solid.
Answer :
Latent’heat of melting (evaporation)

(b) We can get the smell of perfume sitting several meters away.
Answer :
Gases evaporate faster (rate of diffusion is faster)

Question 4.
Arrange the following substances in increasing order to forces of attraction between the particles. Water, Sugar, Oxygen.
Answer :
Oxygen, Water, Sugar

Question 5.
What is the physical state of water at (a) 25°C, (bj 0°C, (c) 100°C?
Answer :
(a) 25°C = Liquid
(b) 0°C = Solid
(c) 100°C = Gases

Question 6.
Give reasons to justify.
(a) Water at room temperature is a liquid.
Answer :
“Required temperature to change the state of matter is more. (Freezing point is 0°, the boiling point is 100°)

(b) An iron almirah is a solid at room temperature.
Answer :
Solid nature require more temperature to change in its state of exciting matter, (room temperature is less)

Question 7.
Why is’ ice at 273 K more effective in cooling than water at some temperature?
Answer :
It corresponds to 0°C requires more temperature to change in its state.

Question 8.
What produces more severe burns, boiling water or stream?
Answer :
Kinetic energy of molecules is more than the molecules at some temperature.

Question 9.
Name A, B, C, D, E and F in the following diagram showing the change in its state.

Answer :
A – Melting point / lignation
B – Vapourisation
C – Condensation
D – Solidification
E – Sublimation
F – Sublimation

Question 10.
Write the symbolic unit representation for the following physical quantities.
Answer :
a. Temperature → K (Kelvin)
b. Volume → m³ (Cubic rnetr
c. Pressure → Pa (Pascal)
d. Weight → N (Newton)
e. Mass → Kg (kilogram)

Question 11.
What do plasma of states of matter mode up?
Answer :
It consists of super – energetic and super exerted particles are in the form of ionized gases.

Question 12.
Mention the factors affecting the evaporation.
Answer :
a. Increase of surface area.
b. Increase of temperature
c. A decrease in humidity
d. Increase in wind speed

Question 13.
Write the numerical relationship between atmosphere and pressure.
Answer :
1 atmosphere = 1.01 x 10⁵ pa.

Question 14.
Expand CNG
Answer :
Compressed Natural Gas

Question 15.
Mention the three instances that arc useful in our daily life of compressed gas.
Answer :
a. LPG (Liquified petroleum gas)
b. Oxygen cylinder in hospitals
c. CNG (Compressed natural gas)

KSEEB Class 9 Science Matter in Our Surroundings Additional Questions and Answers

Question 1.
Why should we wear cotton clothes in summer?
Answer :
Cotton is a good absorber of water helps in absorbing the sweat and exposing it to the atmosphere for easy evaporation.

Question 2.
Expand CNG.
Answer :
Compressed Natural Gas.

Question 3.
Mention the advantages of CNG.
Answer :
Due to high compressibility, large volumes of a gas can be compressed into a small cylinder and transported easily.

Question 4.
Define the melting point of solid?
Answer :
It is a particular temperature at which solid begins to melt and converted into liquid. It is an indication of the strength of the force of attraction between particles.

Question 5.
Why do we see water droplets on the outer surface of a glass containing ice-cold water?
Answer :
The water vapor present in air on coming in contact with the cold glass of water. It loses energy and gets converted to the liquid state.