VI-CHEMISTRY CHAPTER-4 MATTER

SYLLABUS

MATTER-PROPERTIES OF MATTER-STATES OF MATTER-

CHARACTERISTICS OF SOLID, LIQUID AND GAS-

ARRANGEMENT OF ATOMS/MOLECULES IN SOLID,LIQUID AND

GAS- PHYSICAL PROPERTIES OF MATTER.

TOPICS COVERED

MATTER

INTRODUCTION

PROPERTIES OF MATTER

STATES OF MATTER-SOLID,LIQUID,GAS

CHARACTERISTICS OF SOLID LIQUID AND GAS

ARRANGEMENT OF ATOMS/MOLECULES IN SOLID,

LIQUID, AND GAS

INTERCONVERSION OF STATES OF MATTER

PHYSICAL PROPERTIES OF MATTER

CHEMICAL PROPERTIES OF MATTER

INTRODUCTION

The materials which are found in nature are called naturally

occurring materials. You also have seen objects such as Cup,

mugs, bucket, made up of plastic which is also a material.

It is not found in nature but it is made by man and it is called

man-made material.

MATTER

All things are made up of material. Materials are made up of

matter.

Matter is anything that can be perceived by your senses i.e.

you can see, hear, taste smell or touch matter.

For example: air cannot be seen, but you can feel it.

Matter is defined as - Anything which occupies space and has

mass.

PROPERTIES OF MATTER

Matter has mass and occupies space

Mass-The mass of an object is always the same regardless of

where the object is, an object would have the same mass on

the moon on the Jupiter as it has on earth.

Mass is the quantity of matter in an object, whereas weight is

a measure of Earth's pull of gravity on an object.

For example, if you could travel to Jupiter, you would weigh 2.5

times more on Jupiter than on earth, while your mass remains

the same.

Volume -The space occupied by an object is called its VOLUME

Suppose the length, breadth and height of a block is 4 cm, 3 cm

and 5 cm.

Its volume= Length × Breadth × Height

= 4 cm × 3cm × 5 cm =60 cm

The volume of the block is 60 cubic cm. It means that the space

occupied by the block is 60 cubic cm.

STATES OF MATTER

Matter exists in three physical states such as solid, liquid and

gas.

The following are the features associated with the existence of

matter in different states of matter as:

(a) Arrangement of atoms and molecules

(b) Shape and size

(c) Compressibility

(d) Rigidity

(e) Diffusibility

SOLID

Solid matter is highly rigid so it has definitely shape and definite

volume.

Example: wood, iron, brick, glass, stone.

Characteristics

• Rigidity- It is highly rigid.

• Compressibility- solids are incompressible because its

particles are very closely packed. They can expand or contract

to a small extent when heated or cooled.

• Volume -solid have a definite volume

• Shape- solids have their own shape because their molecules

are very tightly packed and cannot move freely.

• Fluidity - they do not flow.

LIQUID

This State of matter is less rigid and can be compressed i.e. the

shape of a liquid can be changed by compressing it. So a liquid

matter does not have a definite shape, but have a definite

volume.

Examples: water, milk, oil etc.

Characteristics

• Rigidity- it is less rigid compared to solid

• Compressibility- can be compressed to a small extent

because the molecules are quite close together and spaces

between them are more.

• Volume- liquids have definite volume.

• Shape- liquids do not have a definite shape but take the

shape of a container because the molecules are free to move

from one direction to another.

• Fluidity- They have a tendency to flow because its particles

can slip slide or glide due to weak intermolecular force of

attraction.

GASES

This state of matter is least rigid and highly compressible so

gases don't have a definite shape or volume.

Examples: carbon-dioxide, oxygen, hydrogen etc.

Characteristics

• Rigidity- Gases are least rigid among all other States of

matter.

• Compressibility- Gases are highly compressible because there

is lot of empty spaces between molecules of a gas.

• Volume- Gases do not have a fixed volume

• Shape Gases do not have a definite shape but take the shape

of a container because the intermolecular space in gas is

maximum and the intermolecular force of attraction is

negligible. So the molecule move freely all around in a closed

container and fill the entire space

• Fluidity- Gases have maximum fluidity because the molecules

of gases move freely.

Click the link below to have better understanding to the topic

https://youtu.be/MrTxRn9MNW

ARRANGEMENT OF ATOMS/MOLECULES IN SOLID,

LIQUID AND GAS.

• Arrangement in solids-

The molecules in a solid are packed close to each other the

only moment they make are small vibrations about their fix

positions the spaces between the molecules are known as

intermolecular spaces these are almost negligible in solid due

to this the molecules attract each other very strong this force of

attraction known as intermolecular force of attraction holds the

molecule together.

• Arrangement in liquid-

The molecules in liquid can move about a little. They are less

tightly packed then in solids i.e. they have bigger

intermolecular space. The molecules of liquid do not have fixed

position. The intermolecular force of attraction between the

molecules of a liquid is weaker than those in solids.

• Arrangement in gas-

The molecules in gases are far apart from one another they

have huge intermolecular space between them they have

almost no intermolecular force of attraction holding them

together, the molecules collide with each other and move in all

directions.

Click the link below to have better understanding to the topic

https://youtu.be/bwGim-eceS

COMPARISON OF SOLID, LIQUID AND GAS.

1. Intermolecular space- There lies space between the

molecules. The space between the molecule is called

intermolecular space.

2. Intermolecular force of attraction- Molecules are held with

each other by a force called intermolecular force of attraction.

More the intermolecular space less is the force of attraction

and vice versa.

3. Movement of molecules- Molecules in matter keep on

moving about the fixed position. More the intermolecular

space, more is the movement of molecules. More the

intermolecular force of attraction, less is the movement of

molecule

4. Volume- less movement of molecule means definite volume

and vice versa

5. Cohesive force- These are attractive forces between similar

molecules

Example: between water-water molecule.

6. Adhesive force- These are attractive forces between

molecules of different material

Example: water molecule and silica

7. Brownian movement- It is the random movement of

microscopic particles suspended in a liquid or gas, caused by

collisions with molecules of surrounding medium.

Example:

• Diffusing in water the particles swirl in random direction

• Beam of light enters in a dark room

8. Shape- More intermolecular force means a definite shape as

molecules are not free to move apart.

9.Diffusion- Diffusion is the process of mixing substance with

each other on their own more is the intermolecular space more

is the diffusion occurs readily in liquid and gases. The molecules

in gases are father apart then the molecules in liquid and solid

and they have a higher speed therefore diffusion occurs more

rapidly in gases than in liquids.

INTERCONVERSIONS OF STATES OF MATTER

Interconversion of States of matter means to change a matter

from one state to another, this change can be brought about by

changing the temperature or pressure of the matter for

example water can be changed from a solid state (ice) into

liquid state by raising the temperature (by supplying heat from

any source) of the solid. Liquid state of water can be changed

into gaseous state (vapour) by for the raising the temperature

to its boiling point 100°C.

TERMS INVOLVED IN CHANGE OF STATE OF

MATTER

• The process of changing a matter from its solid state into its

liquid state by heating is called melting or fusion.

• The process of changing a liquid matter into its vapour or

gaseous state by heating is called vaporization or evaporation.

• The process of changing of a metal from its gaseous state into

its liquid state on cooling is called condensation or liquefaction

• The temperature at which a gas starts changing into its liquid

state is called condensation point.

• The process of changing a liquid matter into its solid state on

cooling is called freezing or solidification.

• The temperature at which a liquid starts changing into its

solid state is called its freezing point.

• The process of changing a solid directly in to its vapor is called

sublimation.

PHYSICAL PROPERTIES OF MATTER.

Physical properties of a matter are those characteristics which

are observed without changing the identity of the matter they

help to distinguish one kind of matter from another. The

Important physical properties of matter are colour, shape,

odour, taste, solubility, melting and boiling points, thermal and

electrical conductivity.

Examples of physical properties of matter

Shapes solids are crystalline having different geometrical

shapes.

Examples: sugar and common salt.

Some solids are amorphous and do not have a definite shape.

Examples: Talcum, powder, flour etc.

Colour -Different substance have different colour.

Example: Gold is yellow (solid) and Copper is pink red (solid)

Chlorine gas is greenish yellow

Taste- most substance have a characteristic taste.

Example sugar (solid) tastes sweet

Salt (solid) tastes salty

Solubility some substance that dissolve in water they are called

water soluble substance

Example: salt, sugar etc

Some substance does not dissolve in water they are called

water insoluble substance

Examples: sand and sawdust etc

Conductivity certain substances allow heat and electricity to

pass through them. They are called good conductors of heat

and light examples iron, copper, Alluminium etc.

CHEMICAL PROPERTIES OF MATTER

• Chemical properties describe matter based on its ability to

change into new matter with different properties

• It can be identified only when new substance has chemical

and physical properties that are different from original

substance

• A chemical reaction takes place when one or more substance

change to form one or more new substances.

• Substances that undergo a chemical change are called

reactants and new substance resulting from this chemical

change are called products

EFFECTS OF HEAT ON MATTER

When heat is added to a body various things can result

• Expansion

• Increase in temperature

• Change of state

• Chemical change

Expansion

When heat is added to a solid, the particles gain energy and

vibrate more vigorously about their fixed positions forcing each

further apart. As a result, expansion takes place. Similarly, the

particles in a liquid or gas gain energy and are forced further

apart. The degree of expansion depends on a substance

For a given rise in temperature, liquid will expand more than a

solid gases expand enormously on heating, causing a possible

expansion if a gas is in a confined space

INCREASE IN TEMPERATURE

When heat energy is added to a substance this result in an

increase in the kinetic energy of its particle i.e. the particles

move at higher speed. Since the temperature is a measure of

the average kinetic energy and the temperature increases.

CHANGE IN STATE

When a solid change to a liquid or a liquid changes to a gas, the

temperature does not change while the change of state is

taking place. The heat absorbed is being used to separate the

particles and there is no rise in temperature when the change is

Reverse exactly the same amount of heat is released. The heat

energy involved in a change of state is called latent heat.

The latent heat of vaporization is defined as the amount of heat

required to change 1 kilogram of a liquid to its gas(vapour) at

its boiling point

CHEMICAL CHANGE

When a substance is heated ,permanent and irreversible

changes occur in which original substance loses its own

composition and properties

Expansion of solids

Solids have three types of expansion namely, linear superficial

and cubical.

When the length of solid increases on heating, it is called

linear expansion.

When the area of solid increases on heating, it is called

areal or superficial expansion.

When the volume of a solid increases on heating, it is

called cubical expansion.

WORKSHEET

Choose the correct option

1. Which of the following is a man-made material?

(a) Water

(b) Wood

(c) Air

(d) Plastic

2. Which of the following is a matter?

(a) Heat

(b) Shadow

(c) Sunlight

(d) Air

3. Water vapour can be changed into water by the process

of ?

(a) Vaporization

(b) Condensation

(c) Melting

(d) Boiling

4. The intermolecular spaces are minimum in cases of?

(a) Solid

(b) Liquid

(c) Gas

(d) Only water

5. Which of the following solid is crystalline?

(a) Common salt

(b) Flour

(c) Talcum powder

(d) Cement

6. The quantity of matter in a body is called ________

(a) Mass

(b) Volume

(c) Weight

(d) Width

7. Smallest unit of substance which can exist

independently.

(a) Molecule

(b) Atom

(c) Compound

(d) Mixture

8. The change of substance from solid to gas is called

________

(a) Crystallization

(b) Condensation

(c) Evaporation

(d) Sublimation

DEFINE 1. Weight- It is a measure of earth’s pull of gravity on an

object.

2. Boiling point- It is the temperature at which liquid

changes to a gas at atmospheric pressure

3. Molecule- It is the smallest particle in a chemical

element or compound.

ANSWER THE FOLLOWING QUESTION 1. What is matter? Name its three physical states.

Ans- Matter is anything that occupies space and has mass.

Solid, liquid and gas.

2. Is the burning of a candlewick a chemical change? Why?

Ans- Yes, because burning of a candlewick produces water

vapour, carbon and carbon-dioxide which cannot be

reversed.

3. Why do liquid take the shape of containers in which they

are placed but not solid?

Ans-Because molecule in liquids are free to move from

one direction to another whereas the molecule of solid are

tightly packed and cannot move freely.

4. What are the factors responsible for the existence of

matter in different states?

Ans- Arrangement of atoms and molecule, shape and size,

compressibility, rigidity, Diffusibility.

5. What are the different effects of heat?

Ans- Expansion, increase in temperature, change of state,

chemical change.

ANSWERS FOR CHOOSE THE CORRECT OPTION

1. Plastic

2. Air

3. Condensation

4. Solid

5. Common salt

6. Mass

7. Molecule

8. Sublimation