NCERT Solutions for Class 9 Science Chapter 2: Is Matter Around Us Pure

Content Curator

The NCERT Solutions for Class 9 Science are provided in this article. Some of the important concepts in Class 9 Science Chapter 2 Is Matter Around Us Pure are:

Download: NCERT Solutions for Class 9 Science Chapter 2 pdf

NCERT Solutions for Class 9 Science Chapter 2

Important Topics in Class 9 Science Chapter 2 Is Matter Around Us Pure?

Matter is any substance that occupies space and has a mass and volume. It exists primarily in three forms: solid, liquid and gas. Any substance, either an element or a compound, that consists of only one type of atom or molecule is defined as pure. For instance, the salt which we use in our kitchen is made up of only one kind of molecule, which is, the Iodine molecule.

Three States of Matter

The three primary states of matter found in our surroundings are solid, liquid and gas. There are several other states of matter found only in specific conditions, like Bose-Einstein condensate and neutron degenerate matter.

Example: How can the states of matter be determined?

Solutions: The components which helps to determine the states of matter are:

The kinetic energy level is a vital component as it impacts the motion of the particles.
The force of attraction between different atoms also helps to determine the state of matter.
The space between every particle.

Colloids

Colloids, otherwise known as colloidal solutions, are a type of mixture where the micro-insoluble particles of one substance are found suspended in another. Colloid, in simple words, refers to a solution which is the size of solute particles ranging between 1nm - 1000 nm.

Example: Determine what happens when a beam of light is passed through a colloidal solution.

Solutions: When a beam of light is passed through a colloidal solution, its path becomes visible. It happens due to the fact that colloidal particles usually have a large enough size to scatter the beam of light passed. This process is otherwise called the tyndall effect.

Suspension

Suspension can be defined as a heterogeneous mixture that comprises many different particles mixed in a solution ranging around a 1000 nanometers. It can be practically seen when solid particles are scattered within a liquid without dissolving in it.

Example: List some of the important properties of Suspension.

Solution: Some of the important properties of Suspension include:

Suspension can be defined as a heterogeneous mixture of solid particles found in a liquid.
Usually in suspension, the particles are visible with the naked eyes.
Normally, the diametric range of the particles are roughly around 1000 nm ( i.e.,100 times that of a solution).

Also Read:

Chapter Related Links
Difference Between Element And Compounds	Difference Between Molecule and Compound	Difference between Physical and Chemical Change
Types of Solutions	Difference Between Mixture And Solution	Colloidal Solutions
Classification Of Colloids	Properties of Colloids	Saturated and Colloidal, Electrolytes, Solute & Solvent

Also Check:

Important Science Study Guides
Named Reactions	Physics Constants	Difference between in biology
Difference between in chemistry	Difference between in physics	Periodic Table

CBSE X Related Questions

1.
Identify the correct statement for spirogyra, leishmania and hydra
- they reproduce sexually.
- they are unicellular.
- they are multicellular.
- they reproduce asexually.
View Solution
2.
Assertion (A): Ozone at higher levels of atmosphere is a product of UV radiation acting on oxygen molecule.
Reason (R): The higher energy of UV splits apart some molecular \( O_2 \).
- Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
- Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
- Assertion (A) is true, but Reason (R) is false.
- Assertion (A) is false, but Reason (R) is true.
View Solution
3.
Assertion : Reaction of quick lime with water is an exothermic reaction. Reason (R): A large amount of heat is evolved on the reaction of quick lime and water.
- Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
- Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
- Assertion (A) is true, but Reason (R) is false.
- Assertion (A) is false, but Reason (R) is true.
View Solution
4.
Which of the following group is not 'biodegradable'?
- Vegetable peels, dead leaves, paper
- Cow dung, leather bag, water
- Polythene bag, rubber band, ball pen
- Paper, fruits, bones
View Solution
5.
The gases evolved on heating lead (II) nitrate crystals are :
- NO and \( O_2 \uparrow \)
- \( N_2 \) and \( NO_2 \)
- \( NO_2 \) and \( H_2 \)
- \( NO_2 \) and \( O_2 \)
View Solution
6.
Sex is determined by different factors in various species. However, in human beings, it is determined genetically. Which amongst the following option(s) is/are correct for human beings ?
Gamete carrying X chromosome from female parent.
Gamete carrying X chromosome from male parent.
Gamete carrying Y chromosome from male parent.
- (ii) and (iii)
- (i) only
- (i) and (iii)
- (iii) only
View Solution