Today we will learn about the amazing world of Matter and its States from Class 4 Science (Chapter - 11} Matter can be solid like a book, liquid like water, or a gas like air. It can change from one state to another - ice melts to water when it gets warm. Learn about the Three States of Matter – Solid, Liquid and Gas.
Answer the following questions
1) What is matter ?
Ans - Any substance that has weight and occupies space is called matter. 2) What are the different states of matter? Ans - Matter exists in three states - Solid, liquid and Gas. 3) Mention the gases that are found in the air? Ans - Air is a mixture of different gases. It contains 78% nitrogen, 21% oxygen and remaining 1% contains carbon dioxide, Argon, helium, water vapour and dust particles. 4) Why does gas move freely in all directions? Ans - The molecules of gas are vary loosely packed. They are far apart from each other. That is why a gas move freely in all directions. 5) What is a solution? Ans - A solution is a homogeneous mixture of one or more solutes dissolved in a solvent. 6. Define the following :
i) Melting :
The process by which a solid changes. into a liquid is called melting.
ii) freezing :
The process by which а liquid changes into a solid is called freezing
iii) Evaporation :
The process by which a liquid changes into Vapour is called evaporation.
iv) Condensation :
The process by which a gas changes into liquid is called condensation.
Fill in the blanks
Matter exists in three states. If a solid is heated it changes into a liquid. In a solution of sugar and water, sugar is the solute and water is the solvent. All matters occupy space and have weight. We find very loosely packed molecules in a gas.
Give one word for the following:
Liquid changing into gas: Evaporation Gas changing into liquid: Condensation Liquid changing into solid: Freezing Ice changing into water: Melling Liquid in which the solute dissolves: Solvent A solution of salt and water : Salty water A state of matter having a definite volume but no definite shape: Liquid.
Points to Remember
Any substance that has weight and occupies space is called matter. Matter is made up of small particles called molecules. Solid, liquid and gas are the three states of matter Solids have a definite shape and volume. Liquids have no fixed shape but a definite volume. Gases have no fixed shape or volume. The three states of matter can be changed into one another. Heating and cooling cause changes in the states of matter. Some solids dissolve in a liquid to form a solution
