NCERT Solutions for Class 3 The World Around Us Chapter 10 This World of Things (PDF) – 2027

Khushi has drawn these things:

1. Light bulb
2. Blackboard
3. Door
4. Electric switch
5. Window frame
6. Bird
7. Rock
8. Mango
9. Mat
10. Chair
11. Table

Yes, we can see through the window glass.

Glass is transparent. Light passes through it. That is why Khushi can see the tree, the mangoes and the bird outside.

I drew the blackboard, the door, two windows, the fan, the light bulb, my desk, my chair and the mat. I wrote the name next to each thing.

People have made these things from materials. The materials come from nature.

• Wood (from trees) — table, chair, door
• Metal (from inside the Earth) — hinges, nails, latches
• Glass (mostly from sand) — windowpanes, bulb
• Plastic — electric switches

We get wood from trees.

The trunk and thick branches of a tree are cut into flat planks. A carpenter joins the planks to make a table or a chair.

Mats are made of cloth, grass or plastic. Bulbs are made of glass. Electric switches are made of plastic.

Why: Glass is transparent, so the light of the bulb comes out through it.

Yes. My classroom window has two glass panes in a wooden frame.

If your window has only iron bars or wooden shutters, write ‘No’.

Yes, we can see through a glass pane.

Glass is transparent. Light passes through it, so we see things on the other side clearly. That is why windows have glass, not wood.

I see a neem tree, the school playground and the road. Birds sit on the wall.

Why: Glass lets the light from outside reach our eyes.

Clean water is transparent. Clear plastic and air are transparent too.

Why: Light passes straight through them, so we can see things on the other side.

Try this: Drop a coin into a glass of clean water. You can still see the coin.

Some translucent materials:

• Oiled paper or butter paper
• A thin polythene bag
• Thin cloth, like a dupatta
• A frosted plastic tumbler
• Frosted glass in a bathroom window

Yes. The white paper looks the same colour as the bag, bottle or cloth we look through. Through a red cloth it looks red. Through a green bag it looks green.

Why: Coloured plastic or cloth lets mostly its own colour of light pass through.

Yes, it looks different. Through thin blue plastic the white paper looks blue. Through thin yellow plastic it looks yellow.

Why: White paper sends back all colours. The coloured plastic lets only its own colour reach our eyes.

Yes, the colours of things also change. A blue object seen through thin yellow plastic looks dark — greenish or almost black.

Sample answer: My blue pen looked dark green, almost black.

• I looked through a green glass bangle. Everything looked green.
• I looked through a coloured plastic bottle.
• I held coloured cellophane paper from a gift in front of my eyes.

the new names are in the third column.

Metals — rocks inside the Earth.

Metal is found in certain rock and sediment, called ore. The ore is dug up from inside the Earth. Then the metal is carefully taken out of it.

Cloth — plants and animals.

Cotton cloth comes from the cotton plant. Woollen cloth comes from the wool (hair) of sheep. The fibres are made into thread, and the thread is woven into cloth.

Did you know? Glass is mostly made of sand!

My grandmother said many things were made of the same materials — wood, metal, glass and clay. But bottles were of glass, not plastic. Buckets were of iron or brass.

Yes. Plastic is the biggest new material.

Sample answer: My grandfather said there were very few plastic things when he was a child. Now we have plastic bottles, chairs, bags and toys. Thermocol is also new for him.

Yes.

Sample answer: My grandmother said clay pots, brass vessels, wooden slates and glass ink bottles were common. Now most homes use steel and plastic, because they are lighter and cheaper and do not break easily.

Yes. Materials are also different in how they feel, bend and sound. We can often tell a material with our eyes closed.

• Touch — metal feels smooth and cold; cloth feels soft.
• Bend — cloth bends easily; wood does not.
• Sound — metal says ‘ting’; wood says ‘thak’.

My spoon is made of steel. Steel is a metal.

Some spoons are made of wood or plastic.

Why: Metal is hard. It does not break or melt in hot food, so most spoons are made of it.

My spoon feels cold, looks shiny and goes ‘ting’ when I tap it. So I guess it is made of metal.

For a steel spoon: smooth, shiny and feels cold to the touch.

The book gives this beat:

Sample answer: my own beat.

Try this: Play it with friends. Each one taps a different material. Together you are an orchestra!

Tables are also made of metal, plastic, glass, bamboo or stone. All of these are hard and do not bend.

No, we cannot.

Fabric and rubber are soft and flexible. They bend when we keep something on them. A table must be hard and rigid, like wood.

Think: Imagine if clothes were made of wood!

A wall of water would flow away. Water cannot keep its shape. Everything in the house would get wet, and no roof could stand on it.

Why: Water is a liquid. A wall needs a solid, like stones or bricks, which keeps its shape.

Tray (solids): a stone, ice, a spoon, a bottle, a bag

Bottle (liquids): ink, honey, water

Balloon (gases): smoke, steam

Why: A solid keeps its shape. A liquid flows. A gas does not stay in a cup. Ice is a solid, even though it is made of water.

• Tray (solids): chalk, book, ball, key, brick
• Bottle (liquids): milk, oil, juice, tea
• Balloon (gases): air, the air inside a football

Flour, sugar and toothpaste.

• Flour and sugar pour like a liquid, but each tiny grain is a solid.
• Toothpaste flows out when we press the tube, but it keeps its shape on the brush.

Natural: tree, mango, bird, stone, water.

Artificial: clothes, shoes, table, pencil, bottle.

Why: Natural things are there in nature. Artificial things are made by people.

Tip: Some natural things are alive, like plants and animals. Some are not alive, like rocks, water and air.

Around June.

Khushi drew ripe mangoes on the tree. A mango tree flowers in winter, around January. The mangoes grow slowly and become ripe in summer, around May and June.

Wood, metal and glass.

• Wood — table, chair, door
• Metal — spoon, nails, key
• Glass — windowpane, bulb, tumbler

Plastic, cloth, clay, rubber and paper are also right.

Paint can shine too, so I would test the spoon.

1. Touch it. Metal feels cold at once.
2. Tap it with another spoon. Metal rings ‘ting’.
3. Lift it. Metal feels heavy for its size.

If it feels cold, rings and is heavy, it is metal.

Natural: tree, bird, stone. Artificial: chair, pencil, bottle.

The matching is:

1. Transparent — A glass used in spectacles
2. Translucent — A lamp shade made of paper
3. Opaque — A plate