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.
The Earth is made of 3 main layers:
1. Crust.
The outer layer.
Thin and solid.
Where we live.
The Earth is made of 3 main layers:
1. Crust.
The outer layer.
Thin and solid.
Where we live.
Fossil record means all the fossils found in rocks, and what they tell us about life on Earth long ago.
Very old, simple life.
Later plants, fish, dinosaurs.
Even later birds, mammals, and humans.
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.
A moving rock is a rock that changes its position from one place to another because of like water, wind, ice, or gravity.
Water – Rivers, floods, and waves can carry rocks of different sizes. Small rocks travel farther; big rocks settle quickly.
Wind – Light rock particles like sand and dust can be blown long distances.
Ice / Glaciers – Glaciers slowly push rocks along as they move downhill.
Weathering is the process by which rocks are broken down into smaller pieces.
Physical weathering is when rocks break into smaller pieces without changing what they are made of.
Chemical weathering is the process in which rocks are changed or broken down by chemical reactions with water, air, or acids, forming new substances.
Metamorphic rocks are rocks that form when rocks change.
Rocks deep inside the Earth get very hot.
Heat makes the particles rearrange.
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.
Sediment is tiny broken pieces of rocks and organic matter that settle down in layers.
Sand on a beach.
Igneous rocks are rocks that are formed when melted rock cools and becomes solid.
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.
Plants grow in it.
Holds water and nutrients.
Rocks are solid materials found on the Earth’s surface. They are made up of one or more minerals.
Granite.
Limestone.
Sandstone.
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.
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.
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.
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.
Acid turns blue litmus red, and alkali turns red litmus blue.
Has a sour taste.
Changes blue litmus to red.
Has pH below 7.
Acids are substances that taste sour and can react with metals.
Example.
Lemon juice.
Vinegar.
Tamarind.
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.
Hard or soft.
Flexible or brittle.
Transparent or opaque .
Metals are strong and shiny, while non-metals are dull and weak.
Shiny and strong.
Conduct heat and electricity.
Malleable and ductile.
Non-metals are materials that are usually not shiny, strong, or conduct heat and electricity.
Not shiny.
Brittle.
Don't conduct heat and electricity.
Metal is a strong, shiny material that can conduct heat and electricity.
Iron, Copper, Gold, Silver, Aluminium.
Metals are used in buildings, vehicles, tools, wires, coins, and jewelry.
Matter changes its state when heat is added or removed.
Matter is made of tiny particles.
These particles move when heated and slow down when cooled.
Ammu, can you explain what is this all about
Melting
Freezing
Evaporation
Condensation
Sublimation
Deposition
Extended
Latent Heat
Change in Kinetic Energy
Intermolecular Forces
Effect of Pressure on State
Effect of Temperature on State
Particle Arrangement During Change
Energy Transfer During Change
Changing States of Matter.
Matter can change when heated or cooled.
Solid to Liquid.
Happens when we heat a solid.
Particles start to move faster.
Everything is made of tiny particles that are always moving and have spaces between them.
Solids: particles vibrate in one place.
Liquids: particles move around each other.
Matter means everything around us.
It can be solid, liquid, or gas.
The states of matter can also change.
Has shape of its own.
An atom is the smallest part of everything.
Example: A hydrogen atom.
Atomic structure means how the atom is made.
Example: In an oxygen atom, protons and neutrons are in the middle, and electrons move around.
Definition: A mixture is when two or more things are mixed but do not join together.
Examples:
Sand and water
Rice and dal
Nuts and raisins
Ammu, this is a very nice post.
How do fossils form?
Why are fossils important? Are they important?