NCERT Solutions for Class 9 Science: Sound

Class 9 is the first stepping stone for a student in the competitive world. With the introduction of the CBSE Board Exam for class 10 a few years back, this has become an important gateway for a student. Based on the results of class 9th a student selects his future stream of Science, Commerce or Arts suiting his interest.

Takshila Learning is providing NCERT Solutions for Class 9 Science as per the latest syllabus by CBSE. Class 9 is the building block for the CBSE Class 10 Board Exams, not only for your exams but also for your higher studies and career. Science is the most essential subject and the knowledge in this field opens up wider career opportunities for the students.

Below you can find the NCERT solution for Class 9th Science. You can get a Solution for the all-important question of “Matter in our Surroundings“

In brief

Ques 1: Which of the following is/are matter?
Chair, air, love, smell, hate, almonds, thought, cold, lemon water, smell of perfume?

Ques 2: 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.

Ques 3: A diver is able to cut through water in a swimming pool. Which property of
matter does this observation show?

Ques 4:What are the characteristics of the particles of matter?

Intext questions – Page no. 7

Ques 1: The mass per unit volume of a substance is called density.
(density=mass/volume). Arrange the following in the order of increasing density – air,
exhaust from the chimneys, honey, water, chalk, cotton and iron.

Ques 2: Answer the following. a) Tabulate the differences in the characteristics of
matter. b) Comment upon the following: rigidity, compressibility, fluidity, filling a gas
container, shape, kinetic energy and density.

Ques 3: 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 a solid.
(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.

Ques 4: Liquids generally have a lower density than solids. But you must have observed
that ice floats on water. Find out why.

Intext questions – Page no. 10

Ques 1: : Convert the following temperature to Celsius scale:
a. 300K
b. 573K

Ques 2 What is the physical state of water at:
a. 250°C
b. 100° C?

Ques 3: For any substance, why does the temperature remain constant during the change
of state?

Ques 4: : Suggest a method to liquefy atmospheric gases.

Intext questions – Page no. 11

Ques 1: Why does a desert cooler cool better on a hot dry day?

Ques 2: How does the water kept in an earthen pot (matka) become cool during summer?

Ques 3: Why does our palm feel cold when we put on some acetone or petrol or perfume
on it?

Ques 4: Why are we able to sip hot tea or milk faster from a saucer rather than a cup?

Ques 5: What type of clothes should we wear in summer?

Intext questions – Page no. 13

Ques 1: Convert the following temperature to Celsius scale.
(a) 293K
(b) 470K

Ques 2: Convert the following temperatures to the Kelvin scale.
(a) 25°C
(b) 373°C

Ques 3: Give reason for the following observations:
(a) Naphthalene balls disappear with time without leaving any solid.
(b) We can get the smell of perfume while sitting several metres away.

Ques 4: Arrange the following in increasing order of forces of attraction between the
particles – water, sugar, oxygen.

Ques 5: What is the physical state of water at –
(a) 25°C
(b) 0°C
(c) 100°C?

Ques 6: Give two reasons to justify –
(a) Water at room temperature is a liquid.
(b) An iron almirah is a solid at room temperature.

Ques 7: Why is ice at 273K more effective in cooling than water at the same temperature?

Ques 8: What produces more severe burns, boiling water or steam?

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