Solid, Liquids and Gases- Class 4 Science- New St. Mery English School

Everything around us is made up of matter, and matter exists in three main forms — solids, liquids, and gases. In this chapter, students will learn how these three states of matter differ from one another based on their shape, volume, and the way their particles are arranged. Through simple examples from daily life, we will understand how solids keep their shape, liquids flow easily, and gases spread everywhere. This lesson will help young learners observe and explore the properties of matter in the world around them.

Solid, Liquids and Gases- Class 4 Science- New St. Mery English School

What is Matter?

Ans:- Any thing that has mass and occupies space is called Matter.

Ex:- plants, animals, people, wood, water, chair, air etc

What are molecules?

Ans:- All matters are made up of small particles , these particles are called molecules.

How many states of matter on the basis of arrangement of particles?

Ans:- There are three states of matter on the basis of arrangement of particles.

          1- Solid

          2- liquid

          3- gas

What is Intermolecular space?

Ans:- The space between the molecules of a matter is called intermolecular space.

What is Solid?

Ans:- matter which have fixed shape and occupies fixed space is called solid.

Ex:- Stone, books, wood etc

What is liquid?

Ans:- matter which do not have fixed shape but occupies fixed space is called liquid.

Ex:- water, juice, milk, honey etc.

What is Gas?

Ans:- Matter which do not have fixed shape and do not occupies fixed space is called gas.

Ex:- oxygen, air, watervapour, carbon dioxide

What is Freezing?

Ans:- The process by which a substance changes from liquid to solid state on cooling is called freezing.

Ex:- When water is kept in freezer, it converts into solid state.

What is melting?

Ans:- The process by which a substance changes from solid to liquid state is called melting.

Ex:- If we heat some ice-cubes, they convert into water.

What is Evaporation?

Ans:- The process of changing liquid state to vapour form is called Evaporation.

Ex:- If we heat water in a pan, It starts boiling and starts changing into water vapours.

What is Condensation?

Ans:- The process by which a substance changes from the gaseous state to the liquid state upon cooling is called condensation.

Ex:- If we cover a lid on the boiling water, on cooling water vapour collects on the lid as water droplets.

What are Soluble substances?

Ans:- The substances that dissolve in water are called Soluble substances.

Ex:- Sugar, Salt etc

What are Insoluble Substances?

Ans:- The substances that do not dissolve in water are called Insoluble substances.

Ex:- Sand, Chalk, Wax etc

What is Solvent?

Ans:- A liquid in which a solute dissolves is called solvent.

Ex:- Water, Milk, etc

What is Solute?

Ans:- A substance that dissolve in a liquid is called Solute.

Ex:- Sugar, Salt etc

What is solution?

Ans:- The mixture that is formed when a solute dissolves in a solvent is called Solution.

Ex:- mixture of water and sugar

How can we separate the soluble substances from solution?

Ans:- We can separate the soluble substances from solution by heating.

Ex:- Salt or sugar can be separated from their solution by heating. The water changes to steam and leaving behind the particles of salt or sugar

How can we separate the Insoluble substances from solution?

Ans:- We can separate the Insoluble substances from solution by Filtration or Sedimentation and Decantation.

Filtration

In this process, insoluble substances can be separated from a mixture with the help of filter paper. Filter paper is a coarse paper with many tiny holes in it through which only liquids can pass.

Ex:- From the mixture of sand particles and water , sand particles can be separated with the help of filter paper. 

Sedimentation and Decantation

In this process sand and mud can be separated from muddy water. Solution should be kept undisturbed for some time. The sand will settle down. This process by which insoluble particles settle down at the bottom is called sedimentation.

Now the clear liquid can be poured slowly to another glass without disturbing it. This process is called decantation. In this method , sand and mud separates from the mixture.