Physical and Chemical Changes

Every day in our surrounding, we see different types of physical and

chemical changes such as growing of trees, rising and setting of the

sun, different shape and size of the moon, burning paper, coal and

wood etc. But, have you ever tried to understand the changes? Let us

look at this concept in-depth.

It is necessary to understand the terms that are physical properties,

chemical properties, reversible and irreversible before knowing the

scientific reason for changes. These do not happen just randomly!

There are many things responsible for these physical and chemical

changes.

Physical and Chemical Changes

● Physical Properties: It is known as shape, size, and state of the

substance. For example, if you take a sheet of paper and fold it

then its shape changes. This change of shape is the physical

properties. Examples include tearing of paper sheet, melting of

wax, melting of ice into water, Frizzing of water, vaporization

process where the change of water into vapour, condensation

process where the change of vapour into the water, Stretching

of a rubber band.

Bending of Metal is a Physical Change but Corossion of Metal is a Chemical Change.

● Chemical Properties: It is the internal properties of a substance.

For example, we can get curd from milk because it is the

product of milk but for each of them, internal properties are

completely different. Examples are: Burning of paper, fuel,

wood or anything.

● Reversible: Some things and processes are there which we can

be reversed this is known as reversible. For example, if you

take a folded sheet of paper this folded sheet of paper also we

can be unfolded. So folding a sheet of paper is a reversible

process. Similarly, we can get back hydrogen and oxygen from

water.

● Irreversible: Some things and processes are there which we

cannot be reverse this is known as irreversible. For example,

when we made curd from milk then again from that curd we

cannot form milk. So this is an irreversible process.

Browse more Topics under Is Matter Around Us Pure

● What are the Types of Pure Substances?

● Introduction and What is a Mixture?

● Separating the Components of Mixture

● What is a Solution?

● Concentration of a Solution

● What is a Colloidal Solution?

● What is a Suspension?

Characteristics of Physical Changes

● In this only, the physical properties of a substance will change

nothing else.

● In this change, no new substance is formed.

● Most of the physical changes that we know are reversible in

nature.

Characteristics of Chemical Changes

● For a substance, only the chemical properties will change.

● Here new substance will form.

● Not all but some of the chemical changes are irreversible.

● By simple physical means, chemical changes cannot be

reversed.

Solved Examples for You

Question: List down the main differences between physical and

chemical changes?

Answer:

Physical Change Chemical Change

1. We cannot find any new substance in a physical change. 1. Here we can find new substance.

2. It is a temporary change. 2.But it is a permanent change

3. This change is reversible. 3.This change is irreversible.

4. In a physical change, very little heat or light energy is usually absorbed or given out.

4. In a chemical change, a lot of heat or energy is absorbed or given out.

5. In a physical change, the mass of a substance does not alter.

5. But in a chemical change, the mass of a substance alter.

What are the Types of Pure Substances?

Have you heard your parents speak of pure and impure water? Do you

know what that means? In this chapter, we will tell you more about it!

Here, we will cover the concepts of pure substances. You will get a

detailed information about the types of pure substances and their

properties. This is a very interesting concept and an important one

from the exam point of view.

Types of Substances

Substances are basically classified into two types. They are:

● Pure Substance: The substances that are free from any kind of

mixture and contain only one kind of particle are pure

substances. Examples of pure substances include iron,

aluminum, silver, and gold.

● Mixtures: Substances that have two or more different particles

are mixtures. Examples of mixture include the salt solution

which is a ‘mixture’ of two components, salt, and water.

Learn more about the Suspension: a Heterogeneous mixture of two or

more substances.

Now that we know what are the basic types of substances, let us cover

the concept of pure substances in more detail.

Types of Pure Substances

Based on their chemical composition, pure substances are classified

into two categories:

1. Elements

2. Compounds

Element

A pure substance that has only one kind of atom and cannot be broken

into two or more simpler substances by physical or chemical means is

an element. Therefore, when you break down gold, you still get gold.

It is an element.

Browse more Topics under Is Matter Around Us Pure

● Physical and Chemical Changes

● Introduction and What is a Mixture?

● Separating the Components of Mixture

● What is a Solution?

● Concentration of a Solution

● What is a Colloidal Solution?

● What is a Suspension?

Characteristics of Elements

● An element is homogeneous in nature; it is a pure substance,

made up of only one kind of atoms. For example, iron and

silver are made of only iron and silver atoms. Therefore, they

are elements.

● An element cannot be broken down into simpler substances by

any physical or chemical methods such as heat, light electricity,

or chemical reactions with other substances. Therefore, when

you break a piece of iron into smaller pieces or heat it, the

piece still remains as the element iron.

● An atom is the smallest unit of an element that shows all the

properties of it. Hence, an atom of iron shows all the properties

of that metal.

● Elements have sharp melting and boiling points.

● Elements are classified as metals, non-metals, and metalloids.

Now, let us look at what metals are and what their properties are.

Metals

Metals are the elements that readily lose an electron to form a positive

ion or a cation. Example: Gold, silver, copper, iron, potassium etc.

Properties of Metals are:

● Metals have lustre. Example: Gold.

● Metals are good conductors of heat and electricity. As metals

have free electrons in them, they are able to conduct heat and

electricity. Example: Copper

● Metals are malleable, meaning that it’s easy to hammer them

into thin sheets. Example: Aluminum

● Metals are ductile, which means they can be drawn into wires.

● Metals are sonorous. They give a ringing sound when they are

hit by a hard iron rod. Example: copper.

● Almost all metals are solids at room temperature.

Yet, there are some exceptions to this. For example, Sodium and

potassium are soft metals. Tungsten is a poor conductor of electricity

and so on. Therefore, it is good if you are aware of the exceptions.

Non-Metals

Non – metals are those elements that readily gain an electron(s) to

form a negative ion or anion. Examples include Hydrogen, Oxygen,

Iodine etc. Properties of non-metals are:

● Non-metals exist as solids, liquids, and gases. Example: Silicon

and carbon are solids; bromine is a liquid; chlorine, fluorine,

and oxygen are gases.

● Non-metals are non-lustrous, that is, they have a dull

appearance. Example: The surfaces of sulfur and phosphorus

do not shine.

● Most non-metals have very low density. Example: Oxygen and

nitrogen are lighter than air.

● Yet, we have the diamond that is a form of carbon. Diamond is

one of the strongest known substances.

● They are not malleable.

● Non-metals, except for carbon are not ductile.

● They are bad conductors of heat and electricity. Yet, graphite is

a good conductor of electricity.

● Non-metals have low melting and boiling points.

Metalloids

The elements which have intermediate properties between those of

metals and non-metals are called metalloids. They are amphoteric in

nature. Metalloids react both with acids and bases. Examples include

boron, silicon, and germanium.

Compound

A pure substance, basically composed of two or more elements and

chemically combined in a fixed proportion is called a compound.

Therefore, water is a compound. It has two elements, hydrogen and

oxygen, combined in a fixed ratio.

Properties of a Compound

● A compound is homogeneous in nature, made up of the same

type of molecules.

● The components of a compound cannot be separated by

physical methods. But, you can separate them by chemical and

electrochemical methods. Therefore, water can be broken down

into hydrogen and oxygen by electrolysis.

● A compound has a fixed composition.

● It has a distinct set of properties which is not similar with the

properties of its constituent elements.

● A compound has a sharp melting and boiling point.

Question For You

Q1. Name one non-metal good conductor of electricity.

Ans: Graphite

Q2. Name one metal that exists in liquid form at room temperature.

Ans: Mercury

Q3. Name one compound that you can break down by the process of

electrolysis.

Ans: Water

Q4. Which forms do non-metals exist in?

Ans: Solid, liquid and gas.

Introduction and What is a Mixture?

You probably come across one or other forms of a mixture in your

daily life. The air that you breathe is the commonest example of a

mixture. Did you know that? Today, we will look at greater depths

into the impure substances or mixtures, as they are commonly called.

In addition to a general introduction, let us discuss all the types and

properties of them in this chapter.

Classification of Matter

First of all, you already know, you can classify matter into two types:

● Pure substances: These are again classified into elements and

compounds.

● Impure substances: All mixtures are considered to be impure

substances.

What is a Mixture?

The majority of substances that we see in our surrounding

neighborhoods are actually not pure substances. They are all mixtures!

Therefore, what are they?

Mixtures are substances composed of two or more forms of matter.

You can separate them by physical methods. Examples include a

solution of salt and water, a mixture of sugar and water, different

gases, air, etc. In any mixture, the various components do not combine

through any kind of chemical changes. Therefore, the components do

not lose their individual properties.

What is solution ?

Types of Mixtures

Based on their composition, they can be divided into two types:

● Homogeneous

● Heterogeneous

Homogeneous Mixture

Mixtures having a uniform composition throughout their bodies are

called Homogeneous Mixtures. For example – a mixture of salt and

water, a mixture of sugar and water, air, lemonade, soda water, etc.

Here, a mixture of salt in water is a classic example. This is because

here, the boundary between salt and water can never be differentiated.

When a ray of light is passed through the mixture of salt and water,

the path of light is not seen.

Properties ● All solutions are examples of a homogeneous mixture.

● The particles in such a case are less the one nanometer.

● They do not show a Tyndall effect.

● You cannot differentiate the boundaries of particles.

● You cannot separate the constituent particles here using

centrifugation or decantation.

● Alloys are examples of a solution.

Want to know more about Concentration Of Solution?

Heterogeneous Mixture

Mixtures lacking a uniform composition throughout are called

Heterogeneous Mixture. Therefore, a mixture of soil and sand, sulfur

and iron filings, oil and water, etc. are heterogeneous as they do not

have a uniform composition. You can identify the various boundaries

of the constituent particles of a homogeneous mixture. This is because

in such a case it has two or more distinct phases.

Properties

● Most of the mixtures are heterogeneous except solutions and

alloys.

● The constituent particles are present uniformly here.

● You can identify the components easily.

● Generally, two or more phases are present in a heterogeneous

mixture.

● The size of the particles here is between one nanometer and

one micrometer.

● They show a Tyndall effect.

Question For You

Q. Define the types of mixtures.

Ans: Based on their composition, you can classify them into two

major types:

● Homogenous mixtures: These are the ones having a uniform

composition throughout their bodies. Examples are a mixture

of salt and water, sugar, and water, air, lemonade, soda water,

etc.

● Heterogeneous Mixtures: These are the ones that lack uniform

composition throughout. Hence, a mixture of soil and sand,

sulfur and iron filings, oil and water, etc.

Separating the Components of Mixture

Do you remember how you used to play with pebbles and sand and

tried to separate those? As grown-ups, you must be in a better position

to understand the different types and components of mixture and how

you can separate those. Let us read all about separation of the

components of mixture in this topic.

Separation of Mixtures

Due to several reasons, separating of mixtures is important. Most of

the materials are there in our surrounding which are the mixtures of

two or more components. For example, when we need to obtain pure

water from dirty water then, we have to purify the substances i.e. dirty

water or we might filter it or distil it. Some techniques are there for the

separation of components from the mixture. Such as:

● Separating Funnel

● Chromatography

● Centrifugation

Browse more Topics under Is Matter Around Us Pure

● Physical and Chemical Changes

● What are the Types of Pure Substances?

● Introduction and What is a Mixture?

● What is a Solution?

● Concentration of a Solution

● What is a Colloidal Solution?

● What is a Suspension?

Separation Techniques For Components of Mixture

Using a separating funnel

Between two immiscible liquid phases, for the separation of

components of the mixture, a separating funnel is used. Two phases

are there one is an aqueous phase and another one is an organic

solvent. Based on the differences in the densities of the liquids the

separation will happen. The liquid with more density they will form a

lower layer and the liquid with lower density forms the upper layer.

Applications

● From a mixture of oil and water to separate the components.

● From a mixture of kerosene oil and water to separate the

components.

Centrifugation

Sometimes the solid particles in a liquid can pass through a filter

paper because of very small size. For those type of particles the

filtration technique, we cannot use for the separation purpose. That

type of mixtures is separated by centrifugation process.Where normal

filtration does not work well, there we can use centrifugation process

of separation of insoluble materials from a liquid.

The centrifugation depends upon the size, shape, and density of the

particles. It also depends on the viscosity of the medium and the speed

of rotation. The theory is that the lighter particles stay at the top when

spun rapidly, the denser particles are forced to the bottom.

Applications

The Centrifuge is the apparatus that is used for centrifugation process.

Centrifuge tube holder is there in a centrifuge which is called rotor.

This rotor has balanced centrifugal tubes by which we can balance

amount of solid-liquid mixture.

The centrifuge tubes rotate horizontally when the rapid rotation of the

rotor happens. The denser insoluble particles separate from the liquid,

due to the centrifugal force. The solid particles end up at the bottom of

the centrifuge tube with liquid at the top, when the rotation stops.

Question For You

Q1. What is the Heterogeneous and Homogeneous mixture?

Ans: A mixture is either homogeneous or heterogeneous. The

Heterogeneous mixture is not uniform in composition. On the other

hand, a homogeneous mixture is a uniform in composition. Air is the

example of homogeneous mixture and oil in water is the example of a

heterogeneous mixture.

They both have several physical methods by which you can separate

the components. Based on the type of mixture and difference in

chemical properties of the constituent of a mixture the choice of

separation technique can be decided.

Q2. What are the different types of separation processes?

Ans: Many techniques are there for the separate the components of the

mixture. Such as:

1. Crystallization

2. Filtration

3. Decantation

4. Sublimation

5. Evaporation

6. Simple Distillation

7. Fractional Distillation

What is a Solution?

Do you know what is a solution? Do you think that the water you

drink or the cola that you enjoy are solutions? Let us tell you more

about it in this section. At times we think, every liquid we see around

us are solutions. However, that is not the case! There are many solid

solutions as well! Surprised? In this chapter, we will discuss more on

what is a solution and which is a type a mixture.

What is a Solution?

What is a solution? Solutions are a homogeneous mixture of two or

more substances. It has homogeneity at the particle level. Usually,

people think of it as some liquid with either a solid or a liquid or a gas

dissolved in it. However, this is not entirely true. We can also have

solid solutions like alloys. For example:

● Air: It is a mixture of gas in gas. Air is a homogeneous mixture

of a number of gases. The two main constituents of gases are

oxygen (21%) and Nitrogen (78%)

● Alloys: Alloys are homogeneous mixtures of metals. They

cannot be separated into their individual components by

physical methods. Irrespective of that, an alloy is considered as

a mixture. It is because an alloy shows the properties of its

constituents and can have variable composition. For example,

brass is a mixture of 30% zinc and 70% copper.

Components of a Solution

The substances that make up a homogeneous solution are called

components of the solution. It has basically has two components i.e. a

solvent and a solute.

● Solvent: The component of a solution which dissolves the other

component in itself is called solvent. A solvent constitutes the

larger component of the solution. For example, a solution of

sugar in water is solid in the liquid. Here, sugar is the solute

and water is the solvent.

● Solute: The component of the solution which dissolves in the

solvent is called solute. The solute is the smaller component of

the solution. For example, a solution of iodine in alcohol

known as ‘tincture of iodine’, iodine is the solute. Similarly, in

carbonated drinks (Soda water), carbon dioxide gas is the

solute.

Characteristics of Solutions

● It is a homogeneous mixture

● The size of solute particles in the solutions is extremely small.

It is less than 1 nm in diameter.

● The particles of a solution cannot be seen even with a

microscope.

● The particles of a solution pass through the filter paper. Thus

filtration cannot separate the solution.

● It is very stable. The particles of solute present in a solution do

not separate out on keeping.

● A true solution does not scatter light (because its particles are

very small).

Concentration of a Solution

The concentration of a solution is the amount of solute present in a

given quantity of it. In other words, the concentration of a solution is

the mass of the solute in grams, which is present in 100 g of a

solution. Depending upon the amount of solute present, it is called a

dilute, concentrated or a saturated solution.

Different substances in a given solvent have different solubilities at

the same temperature. The most common method for expressing the

concentration of a solution is the percentage method. The

concentration of the solutions refers to the percentage of solute present

in the solutions. The percentage of solute can be expressed in terms of

the following two quantities:

● Concentration of solutions in terms of mass of solute

If the solutions have solid solute dissolved in a liquid, then we

consider the ‘mass percentage of solute’ in calculating the

concentration of the solutions. So, in the case of a solid solute

dissolved in a liquid solvent. Mass by mass percentage of the solutions

is given by the percentage of the mass of solute in 100 grams of

solvent.

● Concentration by mass by volume percentage of a solution

Mass by volume percentage of a solute is the percentage of the mass

of the solute present in the specific volume of the solvent. Depending

upon the unit of the mass and volume, the mass by volume percentage

of solute in solutions can have following units as gram/ml or

gram/litre.

● Solubility of a Solute

Solubility is the amount of solute (in gram), which dissolves in 100 g

of water (solvent), at a given temperature.

Types of Solutions

● Saturated Solutions: Saturated solutions are solutions

dissolving as much solute as it is capable of dissolving at a

given temperature.

● Unsaturated Solutions: Unsaturated solutions are the ones with

a lesser amount of solute than what we require for saturation.

Sometimes, by applying external forces like heat energy, you

can increase the solubility of the solutes in the solutions.

● Supersaturated Solutions: Supersaturated solutions contain

more solute than saturated solutions.

Solved Examples for You

Question: Write a note on Brownian movement in colloids.

Answer: The colloidal particles move at random and zig-zag motion in

all directions. This type of random motion of the particles denotes the

Brownian movement. The main reason behind such. movement is the

collision of various particles against each other.

Concentration of a Solution

Have you heard your parents talk about the concentration of a

particular solution? It is a daily life discussion in almost every

household. And, mind you, we are not talking about the concentration

that you are asked to put in your studies! In this chapter, we let you

put your concentration on learning about the concentration of a

solution!

What do you mean by Concentration of a Solution?

The concentration of a solution is the amount of solute present in a

given quantity of the solution. In other words, the concentration of a

solution is the mass of solute in grams present in 100 g of the solution.

Based on this definition, there are two main types of solutions.

The solution that has a small amount of solute is called Dilute

Solution. The solution that has a large amount of solute is called

Concentrated Solution. This is a very narrow division of solutions. Let

us now look at the types of solution in more depth.

● Saturated Solution: A saturated solution is one in which you

cannot dissolve any more quantity of solute at a given

temperature. It means that this kind of solution already contains

the maximum amount of solute that you can dissolve in it at a

given temperature.

● Unsaturated Solution: An unsaturated solution is one in which

you can dissolve more quantity of solute at a given

temperature.

Browse more Topics under Is Matter Around Us Pure

● Physical and Chemical Changes

● What are the Types of Pure Substances?

● Introduction and What is a Mixture?

● Separating the Components of Mixture

● What is a Solution?

● What is a Colloidal Solution?

● What is a Suspension?

Test for Saturation

In order to test whether or not a given solution is saturated, we should

add some more solute to this solution and try to dissolve it by stirring.

If it does not dissolve, then it will be a saturated solution but if it

dissolves, then it is an unsaturated solution. However, if a particular

saturated solution at a particular temperature is heated to a higher

temperature, then it becomes unsaturated.

Why Does This Happen? This happens because on applying more

heat, the solubility of solute increases. Thus, you can dissolve more of

solute by raising the temperature of the solution. If you cool a

saturated solution to a lower temperature, then some of its dissolved

solutes separate out in the form of solid crystals. This is because the

solubility of the solute in the solution decreases on cooling.

The Solubility of a Solution

The solubility of a solute in a solvent is the maximum amount of a

solute that dissolves in 100 g of a solvent at a specified temperature.

For example, you can dissolve 36 g of NaCl in 100 g of water at 20°C.

Therefore, the solubility of NaCl in water is 36 g at 20°C. To be able

to calculate the solubility of a substance, we need to find the mass of

substance dissolved in 100g of water.

Effect of Temperature and Pressure on Solubility

● The solubility of solids in liquids increases upon increasing the

temperature and decreases upon decreasing the temperature.

Therefore, the temperature has a direct effect.

● The solubility of solids in liquid remains unaffected by any

changes in pressure. Therefore, the pressure will have no effect.

● Pressure has a direct effect on the solubility of gases in liquids.

Therefore, the solubility of gases in liquid increases on

increasing the pressure and decreases on decreasing the

pressure.

Solved Example For You

Question: Discuss the effect of temperature on the solubility of gases.

Answer: Temperature has an indirect effect on the solubility of gases

in liquids. Therefore, the solubility of gases in liquid usually decreases

when we increase the temperature. It increases in decreasing the

temperature.

What is a Colloidal Solution?

In this chapter of chemistry, we will introduce you to another form of

matter, known as colloids and their solution, known as a colloidal

solution. We are sure you know quite a bit about these solutions.

However, we are going to dig further into the chapter, looking at their

properties, types, and examples.

What are Colloids or Colloidal Solution?

Colloidal solutions, or colloidal suspensions, are nothing but a mixture

in which the substances are regularly suspended in a fluid. A colloid is

a very tiny and small material that is spread out uniformly all through

another substance.

Learn more about Stabilization and Application of Colloid here.

Colloidal systems can occur in any of the three key states of matter

gas, liquid or solid. However, a colloidal solution usually refers to a

liquid concoction. The primary distinguishing feature between a true

solution and a colloidal solution is fundamentally the dimensions of

the constituent parts.

Browse more Topics under Is Matter Around Us Pure

● Physical and Chemical Changes

● What are the Types of Pure Substances?

● Introduction and What is a Mixture?

● Separating the Components of Mixture

● What is a Solution?

● Concentration of a Solution

● What is a Suspension?

True Solution and Colloidal Solution

In a true solution, like salt water, NaCl molecules are totally mixed in

the water, and the solution can pass through a semi-permeable film

without getting divided. On the other hand, in a colloidal solution, the

units are bigger and they don’t liquefy. However, they are equally

dispersed all through a liquid. As such these units will not pass

through a membrane as the liquid does.

Learn about Homogenous and Heterogenous Mixture here.

Classification of Colloidal Solution

Colloidal Solutions are divided into the following types:

● Foam: Foam is a solution of a gas in a liquid. The substance

being dispersed would be the gas, triggering the fluid to

become frothy and foamy. A sample of this would be shaving

cream.

● Emulsion: An emulsion is a combination of liquids. It is

basically when one liquid is consistently dispersed all through

another liquid. A sample of this would be mayonnaise or milk.

Learn more about Emulsion here.

● Sol: The third form is called a sol. A sol is a combination of a

solid that is evenly dispersed throughout a fluid. Samples of

sols include paint, blood and silver aquasols.

● Hydrocolloid: A hydrocolloid is a more detailed form of a

colloidal solution. In this solution, the fluid of a precise

material is properly disseminated in water. Hydrocolloids are

usually used in food products to influence texture, as in sauces

or gelatins.

● Reversible or Irreversible Colloids: The colloidal solutions can

be additionally labeled as being reversible or irreversible. In

reversible colloids, the two materials can be effortlessly

divided again whereas, in irreversible ones, this is not possible.

Question For You

Q. Give two practical applications of colloidal solutions in our daily

life.

Ans: In our ordinary surroundings, colloidal solutions are significant

in many procedures, and can often assist as transporters. Numerous

particles being conveyed through water can basically attach

themselves to the units suspended in the water.

By the same process, colloidal solutions can assist in the conveyance

of more harmful substances through the water table, for example,

radioactive material. Colloidal solutions are very important in the

medicinal field as they can be used to influence blood conditions.

More precisely, they are frequently used to control colloidal osmotic

pressure, the pressure exerted by proteins in the bloodstream to entice

water in the vascular system.

What is a Suspension?

In this chapter, we will talk about a suspension. Are you aware of

what is it actually? You must have come across many such examples

in your daily life. Right? Let us now look at these types of solutions in

a more detailed manner. We will discuss their properties and

characteristics. We will also elaborate some examples for you.

What is a Suspension?

A suspension is a heterogeneous mixture of two or more substances.

In it, the particles are suspended throughout the solution in bulk and

can be easily seen by naked eyes. Here, the particles of the solute do

not dissolve in the solution and are rather suspended. Particles of the

suspension are large enough to scatter the rays of light and the path of

ray is visible through it.

Some of the common examples of include:

● Mixture of chalk and water

● Muddy water

● Mixture of flour and water

● Mixture of dust particles and air

● Fog

● Milk of magnesia, etc.

Browse more Topics under Is Matter Around Us Pure

● Physical and Chemical Changes

● What are the Types of Pure Substances?

● Introduction and What is a Mixture?

● Separating the Components of Mixture

● What is a Solution?

● Concentration of a Solution

● What is a Colloidal Solution?

General Characteristics and Properties of Suspension

● Suspensions are a heterogeneous mixture of two or more

substances.

● Particles of the solute do not dissolve in the solvent rather they

remain suspended in bulk throughout.

● The size of particles of suspension is large enough to be visible

from naked eyes. They are greater than 1 nanometer (?10?^(-9)

meter).

● It shows Tyndall effect because of their large size of particles.

● When it is left for some time, particles get settled in the bottom.

Therefore, it is not stable.

● The particles in it can be separated through the process of

filtration.

● It does not scatter light when particles are settled because in

this case suspension breaks.

Question For You

Q1. Give some examples of suspension.

Ans: Common examples of suspension include the mixture of chalk

and water, muddy water, the mixture of flour and water, a mixture of

dust particles and air, fog, milk of magnesia, etc.

Q2. Give the definition of suspension.

Ans: A suspension is a heterogeneous mixture of two or more

substances. Here, the particles are suspended throughout the solution

in bulk and can be easily seen by naked eyes. In it, particles of the

solute do not dissolve in the solution and are rather suspended.

Particles of the suspension are large enough to scatter the rays of light

and the path of ray is visible through it.