4th Class Science States of Matter Soild, Liquid and Gas States of Matter Solid, Liquid and Gas

LEARNING OBJECTIVES

This lesson will help you to:—

• learn about matter.
• study different states of matter.
• know how one state changes into another state.

Real Life Examples

When a container containing ice cubes is placed in sunlight it can be observed that first it melts down to form liquid water. And then if it is left undisturbed in sunlight till evening. Some of the water gets evaporated. In the atmosphere and the quantity of water in the container gets reduced.

Due to the increasing temperature of the earth, glaciers are melting, leading to the increase in the water level of the earth.

QUICK CONCEPT REVIEW

What is Matter?

• Matter is something that has mass and occupies space.
• Matter is made of particles.
• The particles of matter are very small.
• The particles of matter are moving continuously.
• Particles of matter have space between them.
• Particles of matter attract each other because of force of attraction.

STATES OF MATTER

There are three states of matter;

• Solid
• Liquid
• Gases

SOLID

• Has a definite shape.
• Has a definite volume.
• Molecules in a solid are very tightly packed.
• We cannot compress it.
• Solids are heavy.
• Solid does not flow.

       Example: Diamond.

LIQUID

• Has no definite shape as it takes the shape of its container.
• It has definite volume.
• Molecules are loosely packed.
• It can be compressed.
• Liquid is lighter than solid..
• Liquid flows and hence is called fluid.

Example: Water.

GASES

• Have neither definite shape nor volume.
• They are easily compressible.
• Molecules are far apart.

Example: Steam.

Amazing Facts

Glass is actually a liquid; it just flows very, very slowly.

Liquid oxygen is blue.

Hot water freezes quicker than cold water

CHANGE OF STATE

Matters can be changed from one state to another state. A solid can be changed into liquid and a liquid can be changed into gas. Most of the metals, which ore solid, turn into liquid on heating and turn into vapour on further heating.

Misconcept/Concept

Misconcept: The shape of solids does not change.

Concept: Solids can be changed into another form by applying temperature or pressure.

Misconcept: There is no space between the particles of solids.

Concept: There are very small spaces between the particles of solids.

Process of change of states of matter:

• Melting: The change of solid into liquid due to increase in temperature is known as melting.
• Evaporation: The process of change of water into vapour is called evaporation.
• Condensation: The change of vapour into water because of decrease in temperature is called condensation. It is the reverse of evaporation.
• Freezing: The change of liquid into solid because of decrease in temperature is called freezing.

SHORTCUT TO PROBLEM SOLVING

\[solid\xrightarrow{Increase\,in\,temperature}Liquid\xrightarrow{Increase\,in\,temperature}Gas\] \[Gas\xrightarrow{Decrease\,in\,temperature}Liquid\xrightarrow{Decrease\,in\,temperature}Solid\]