• Solid – Has a fixed shape and fixed volume. Its particles are packed closely together and mainly vibrate in place.

• Liquid – Has a fixed volume but no fixed shape. It takes the shape of its container, and its particles can move past one another.

• Gas – Has no fixed shape or volume. Its particles are far apart and move freely in all directions.

• Plasma – A very high-energy state of matter made of charged particles. It occurs naturally in things like stars and lightning.

• Bose–Einstein condensate (BEC) – Forms at extremely low temperatures. Particles behave collectively as though they are one quantum system.

• Superfluid – A special state of matter that can flow with extremely little resistance. It occurs at very low temperatures.

A chemical reaction is when one or more substances change into completely new substances.

Example:

When you burn wood:

• Wood + oxygen → ash + gases

• The new substances have different properties from the wood.

Key points:

Definition:

Dissolving is when a substance, called the solute, mixes completely with a liquid, called the solvent, and seems to disappear. The substance is still there, but it has spread evenly through the liquid.

Key Points:

• A solute (such as sugar or salt) dissolves in a solvent (such as water).

• The solute does not disappear—it is still in the liquid.

• The mixture formed is called a solution.

What are Rocks?

Rocks are natural solid materials that make up the Earth's crust. They are found everywhere on Earth, including mountains, hills, riverbeds, deserts, and under the oceans. Rocks are an important part of our planet because they help form landforms, provide minerals, and eventually break down to form soil.

Rocks are made up of one or more minerals. Some rocks contain only one mineral, while others contain several different minerals mixed together. The minerals present in a rock determine its colour, texture, hardness, and other properties.

Rocks are formed naturally over millions of years through different geological processes. They can be very hard, like granite, or relatively soft, like chalk. Some rocks are smooth, while others are rough or layered.

Types of Rocks

1. Igneous Rocks

Rocks

Rocks are natural solid materials that make up the Earth’s crust. They are found everywhere on land, mountains, riverbeds, and even under the sea.

Rocks are made of one or more minerals. Some rocks are made from only one type of mineral, while others are made from many minerals mixed together.

There are different types of rocks:

Acids and Alkalis

What Are Acids?

Acids are substances that can react with other materials and usually have a sour taste.

Examples of Acids

• Vinegar

• Lemon juice

What is the Geological Time Scale?

The geological time scale is a timeline of Earth’s history. It shows when major events happened, like:

• Formation of Earth.

• Appearance of plants and animals.

• Mass extinctions.

• Evolution of humans.

Structure of the Earth.

The Earth is made of 3 main layers:

1. Crust.

• The outer layer.

• Thin and solid.

• Where we live.

Structure of the Earth.

The Earth is made of 3 main layers:

1. Crust.

• The outer layer.

• Thin and solid.

• Where we live.

Fossil record.

Fossil record means all the fossils found in rocks, and what they tell us about life on Earth long ago.

What does the fossil record show?

• Very old, simple life.

• Later plants, fish, dinosaurs.

• Even later birds, mammals, and humans.

Definition.

When a plant or animal dies.

• It gets buried by mud, sand, or soil.

• Over a very long time, these layers turn into rock.

• The body or its mark is saved inside the rock.

Types of fossils.

Definition.

A moving rock is a rock that changes its position from one place to another because of like water, wind, ice, or gravity.

How rocks move.

1. Water  – Rivers, floods, and waves can carry rocks of different sizes. Small rocks travel farther; big rocks settle quickly.

2. Wind – Light rock particles like sand and dust can be blown long distances.

3. Ice / Glaciers – Glaciers slowly push rocks along as they move downhill.

Weathering.

Weathering is the process by which rocks are broken down into smaller pieces.

Physical Weathering.

Physical weathering is when rocks break into smaller pieces without changing what they are made of.

Chemical weathering.

Chemical weathering is the process in which rocks are changed or broken down by chemical reactions with water, air, or acids, forming new substances.

Definition.

Metamorphic rocks are rocks that form when rocks change.

How they change.

1. Heat.

• Rocks deep inside the Earth get very hot.

• Heat makes the particles rearrange.

What are Sedimentary Rocks?

Sedimentary rocks are rocks formed from layers of small pieces of rocks, minerals, and remains of plants and animals that get pressed together over a long time.

Definition.

Sediment is tiny broken pieces of rocks and organic matter that settle down in layers.

Example.

• Sand on a beach.

What is Igneous Rock?

Igneous rocks are rocks that are formed when melted rock cools and becomes solid.

How they are formed.

• Deep inside Earth, rocks melt and become magma.

• When magma comes out of a volcano, it is called lava.

• When magma or lava cools, it hardens and forms igneous rock.

What is Soil?

It is the top layer of the ground where plants grow.

Why Soil is Important.

• Plants grow in it.

• Holds water and nutrients.

How Many Layers Are There in Soil?

1. What are Rocks?

Rocks are solid materials found on the Earth’s surface. They are made up of one or more minerals.

Examples.

• Granite.

• Limestone.

• Sandstone.

1. What it is

• Test if a substance is acid, alkali, or neutral.

• Know if it’s strong or weak.

• Test everyday items like lemon juice or soap.

• Shows how they react.

2. How to test

1. What is Neutralisation in Action

• It is neutralisation happening in real life.

• An acid and an alkali react with each other.

• They cancel each other out.

• They form salt and water.

• You can see a change happening.

1. What is Neutralisation

• Neutralisation is a reaction between an acid and an alkali.

• They cancel each other out.

• The reaction makes salt and water.

• The final solution becomes neutral.

2. How Neutralisation Happens

pH scale.

A number scale from 0 to 14 that tells us if something is an acid neutral or alkali.

• 0 to 6 = acid.

• 7 = neutral.

• 8 to 14 = alkali.

How it works.

How to Tell if Something is an Acid or an Alkali.

Acid turns blue litmus red, and alkali turns red litmus blue.

Acid.

• Has a sour taste.

• Changes blue litmus to red.

• Has pH below 7.

What are Acids?

Acids are substances that taste sour and can react with metals.

Example.

• Lemon juice.

• Vinegar.

• Tamarind.

Everyday Materials and Their Properties.

Everyday materials are the things we use in daily life like wood, plastic, metal, glass, paper and cloth. Each material has special properties that make it useful for certain purposes.

Properties of Materials.

• Hard or soft.

• Flexible or brittle.

• Transparent or opaque .

Comparing Metals and Non-metals.

Metals are strong and shiny, while non-metals are dull and weak.

Metals.

• Shiny and strong.

• Conduct heat and electricity.

• Malleable and ductile.

What is a Non-metal?

Non-metals are materials that are usually not shiny, strong, or conduct heat and electricity.

Properties of Non-metals.

• Not shiny.

• Brittle.

• Don't conduct heat and electricity.

What is a Metal?

Metal is a strong, shiny material that can conduct heat and electricity.

Examples.

Iron, Copper, Gold, Silver, Aluminium.

Uses.

Metals are used in buildings, vehicles, tools, wires, coins, and jewelry.

Explaining Changes of State.

Matter changes its state when heat is added or removed.

Why it happens.

Matter is made of tiny particles.

These particles move when heated and slow down when cooled.

When we add heat.

Changing States of Matter.

Matter can change when heated or cooled.

1. Melting.

Solid to Liquid.

Happens when we heat a solid.

• Particles start to move faster.

Particle Theory

What is Particle Theory?

Everything is made of tiny particles that are always moving and have spaces between them.

Movement of Particles.

• Solids: particles vibrate in one place.

• Liquids: particles move around each other.

States of Matter.

Matter means everything around us.

It can be solid, liquid, or gas.

The states of matter can also change.

1. Solid.

• Has shape of its own.

 Atom

An atom is the smallest part of everything.

Example: A hydrogen atom.

Atomic Structure

Atomic structure means how the atom is made.

Example: In an oxygen atom, protons and neutrons are in the middle, and electrons move around.

Mixture

Definition: A mixture is when two or more things are mixed but do not join together.

Examples:

1. Sand and water

2. Rice and dal

3. Nuts and raisins