Everything around us is made of materials. The chair you're sitting on, the clothes you’re wearing, and the food you eat — all are made from different kinds of materials. Materials can be anything from the metal in your spoon to the plastic in your water bottle. We can group materials based on their properties — how they feel, what they look like, and what they can do. Some materials are hard, like metal, while others are soft, like cotton. Some materials can bend, like rubber, and others cannot, like glass. Understanding the different types of materials helps us choose the right one for a particular purpose. For example, we use glass to make windows because it is clear and lets light in, but we use metal to make cars because it is strong and protects us.
Objects around us are made from different materials. A material is a substance used to make an object. For example, a wooden table is made from the material wood. Let’s explore some common materials around us
We must group substances around us to understand them better. Grouping helps us search things more easily and see how they are similar or different. For example, in a supermarket , different items are grouped in each shelf and sections to make it easy for customers to find them.
These materials are found naturally and are obtained from plants, animals, or minerals.
These materials are made by humans using natural materials or synthetic processes.
The earliest pottery found in the Indian subcontinent dates back to 7,000 to 8,000 years ago in the Ganga plains (Lahuradewa) and in Baluchistan (Mehrgarh). Around 4000 BCE, the Sindhu-Sarasvati region developed advanced pottery techniques, including wheel-turned pottery, use of colors (called ‘slips’), and decorative painting. During the Sindhu-Sarasvati (Harappan) Civilisation (2600–1900 BCE), these techniques became highly sophisticated. Pottery featured a bright red surface with black designs, showing geometric patterns and images of aquatic and land animals. Clay was carefully chosen, cleaned, sieved, kneaded, shaped on a wheel, and then baked in kilns. The baked clay pottery is known as terracotta. These pots and vessels were used for cooking and storing food grains, oil, ghee, and other items. Some large storage jars and other pottery pieces from this period are displayed at the National Museum, New Delhi.
Materials around us have different appearances. For example: Unpolished wood looks dull and rough. Metals like iron, copper, and aluminium have shiny surfaces and smooth textures. Even though these metals look different from each other in color or shape, they still share some key similarities—like their shine (lustre)—that set them apart from materials like wood or paper.
Instructions:
|
Material |
Shiny (Yes/No) |
Texture (Smooth/Rough) |
Lustrous or Non-Lustrous |
Notes |
|
Copper wire |
Yes |
Smooth |
Lustrous |
Metal |
|
Aluminium foil |
Yes |
Smooth |
Lustrous |
Thin metal sheet |
|
Chalk |
No |
Rough |
Non-Lustrous |
Crumbly |
|
Cardboard |
No |
Rough |
Non-Lustrous |
Dull surface |
|
Brass item |
Yes |
Smooth |
Lustrous |
Alloy metal |
|
Wood |
No |
Rough/Smooth |
Non-Lustrous |
Depends on polish |
|
Steel spoon |
Yes |
Smooth |
Lustrous |
Stainless steel |
|
Paper |
No |
Smooth |
Non-Lustrous |
No shine |
??No! Not all shiny materials are metals. Some non-metals or non-metallic objects appear shiny because they are polished or coated with substances like Plastic, wax and metallic paints. Think about the phrase: “All that glitters are not gold.” This means that not all shiny materials are truly valuable metals, and not all shine comes from metal.
When you press different materials with your hand, you’ll notice that, some materials like stone or iron rods are difficult to press or compress. While others, like sponges or erasers, can be easily compressed. Another way to compare their hardness is by using a metal key. Try scratching the surfaces of different objects such as wood, stone, wax, chalk to understand the hardness. You must note that, hardness is relative which means a material might be harder than one object but softer than another.
Example: Rubber is harder than sponge, but softer than iron.
|
Material/Object |
Can Be Scratched Easily? |
Can Be Pressed Easily? |
Hard/Soft |
|
Stone |
No |
No |
Hard |
|
Chalk |
Yes |
Yes |
Soft |
|
Wood |
Slightly |
No |
Medium |
|
Iron rod |
No |
No |
Hard |
|
Rubber ball |
Yes (barely) |
Yes |
Soft |
|
Sponge |
Yes |
Yes |
Very Soft |
|
Candle wax |
Yes |
Yes |
Soft |
Transparency of materials is the property which one can see or cannot see. Have you ever looked through glass or clean water and seen things clearly on the other side? That’s because such materials are transparent. But what happens when you try to look through a wooden door or a metal box? You can’t see anything — those are opaque. Now try looking through butter paper or frosted glass. You can see some light, but not clearly. These are translucent materials.
|
Type of Material |
Description |
Examples |
|
Transparent |
Allows light to pass through completely. You can see objects clearly. |
Glass, clean water, air, cellophane |
|
Translucent |
Allows some light to pass, but not clear enough to see objects clearly. |
Butter paper, frosted glass |
|
Opaque |
Does not allow light to pass. You cannot see through them. |
Wood, cardboard, metal |
Collect these items from your home or classroom:
Task: Try looking through each and classify them as Transparent, Translucent, or Opaque.
|
Object |
Can You See Through? |
Type |
|
Cellophane paper |
Yes, clearly |
Transparent |
|
Butter paper |
A little light passes |
Translucent |
|
Steel plate |
No |
Opaque |
|
Drinking glass |
Yes, clearly |
Transparent |
|
Cardboard |
No |
Opaque |
Water is called a "universal solvent" because it can dissolve many substances.
In our body, water helps to dissolve food, medicines, and minerals so they can be absorbed and used properly. When you mix things with water, you may notice that some materials disappear, while others stay undissolved or float. This happens because some materials are soluble, and others are insoluble in water.
Mix each of these materials with water. Stir well and observe whether they dissolve.
|
Material |
Prediction |
Observation |
Soluble/Insoluble |
|
Sugar |
Yes |
Dissolves |
Soluble |
|
Salt |
Yes |
Dissolves |
Soluble |
|
Chalk powder |
No |
Settles down |
Insoluble |
|
Sand |
No |
Settles down |
Insoluble |
|
Sawdust |
No |
Floats |
Insoluble |
|
Tea powder |
No |
Suspends |
Insoluble (filterable) |
When you pour different liquids into water, they may behave differently: Miscible liquids are those that mix well with water (like vinegar or lemon juice). Immiscible liquidsdo not mix and form separate layers (like oil). Oil is less dense than water, so it stays on top.
|
Liquid |
Mixes with Water? |
Observation |
|
Lemon juice |
Yes |
Mixes completely |
|
Milk |
Partially |
Appears mixed but cloudy |
|
Oil |
No |
Floats on top and forms a layer |
|
Vinegar |
Yes |
Mixes completely and remains clear |
Just like solids and liquids, some gases can dissolve in water. Aquatic life depends on dissolved oxygen. If water lacks oxygen, fish and plants may die.
|
Gas |
Soluble in Water? |
Importance |
|
Oxygen |
Yes |
Needed by fish and aquatic animals |
|
Carbon dioxide |
Yes |
Used by aquatic plants in photosynthesis |
|
Nitrogen |
Slightly |
Not used directly by aquatic life |
|
Hydrogen |
No |
Insoluble |
ORS helps treat dehydration caused by diarrhoea or heat. When someone has diarrhoea, they lose water and salts from the body. This can lead to dehydration, which is dangerous—especially for small children. ORS helps the body regain lost fluids and maintain salt balance. ORS should taste slightly sweet and salty. It's safe and can save lives. Home Recipe for ORS is given in the table below.
|
Ingredient |
Quantity |
Why it’s important |
|
Clean water |
1 litre (boiled & cooled) |
Hydration |
|
Sugar |
6 teaspoons |
Provides energy |
|
Salt |
½ teaspoon |
Replaces lost salts/electrolytes |
Steps:
is the amount of matter in an object. We use mass to tell how heavy or light something is. In everyday life, we often say “ weight” when we actually mean “mass.” If an object is heavier, it has more mass.If an object is lighter, it has less mass.
|
Unit |
Symbol |
Used For |
|
Gram |
g |
Light objects like fruits, paper |
|
Kilogram |
kg |
Heavier objects like a bag of rice |
|
Milligram |
mg |
Very tiny objects like medicine |
|
Object |
Heavier or Lighter |
Reason |
|
Metal spoon |
Heavier |
Made of dense material (metal) |
|
Sponge |
Lighter |
Contains air, less dense |
|
Stone |
Heavier |
Solid and compact |
|
Empty plastic bottle |
Lighter |
Hollow and made of plastic |
|
Object |
Approximate Mass |
|
1 apple |
200 g |
|
A schoolbag |
4–5 kg |
|
A grain of rice |
20–30 mg |
|
1 bottle of water (1 L) |
6 kg |
Measuring Volume of Liquids
|
Unit |
Symbol |
Example |
|
Liter |
L |
A bottle of water holds 1 L |
|
Milliliter |
mL |
A small medicine bottle has 50 mL |
|
Unit |
Symbol |
Example |
|
Cubic centimeter |
cm³ |
A small toy block might be 10 cm³ |
|
Cubic meter |
m³ |
A large box could be 1 m³ |
Take a water bottle and check how much water it holds (in liters or milliliters). Fill different containers with water and measure their volume. Try comparing the space occupied by different objects (e.g., a book vs. a shoe box).
|
Object |
Approximate Volume |
|
Glass of water |
250 mL |
|
Small ball |
100 cm³ |
|
Shoe box |
30,000 cm³ (or 0.03 m³) |
|
Swimming pool |
50,000 L (or 50 m³) |
Matter is anything that occupies space and has mass. In other words, every solid, liquid, and gas around you is made of matter. Mass measures how much “stuff” an object contains, using units like grams (g) or kilograms (kg). Volume measures how much space that “stuff” takes up, using units like litres (L), millilitres (mL), or cubic metres (m³).
Answer
|
I observe |
Materials they are made up of |
|
Table |
Wood |
|
Bottle |
Plastic |
|
Chair |
Iron |
|
Bulb |
Glass |
Activity 6.3: Let us think
Answer: Materials which can be used to make tumbler are Glass, Clay, Iron, Plastic, Bamboo, Aluminium, and steel.
Answer
No, it is not a good idea to use paper like materials for making utensils as the paper will get burnt under high temperature and flame. Also, it will get wet due the liquid content of food.
Answer
Tumbler cannot be made of cloth for storing water because the cloth is porous and water will pass through it. Cloth is not able to store water.
Activity 6.6: Let us classify
Answer
Answer
Yes, water in its natural form is transparent. It can be made opaque by dissolving other materials like mud, colour etc.
Answer
No, everything we put in water does not disappear. Only the materials which are soluble in water disappear when mixed with water in limited amount.
Answer
Properties like mass and volume is shown by all materials.
Answer
Glass → Transparent
Wood → Opaque
Iron → Lustrous
Bottle → Plastic
Copper → Solid
Students should randomly choose nine words from the given list and write them in the grid. The teacher either reads the meaning of a word or the word itself from the given list. The learner must tick if the particular word is there in the grid. Whoever finishes all words at the earliest , he/she is winner if his/her words are marked correctly.
Answer:
|
lustrous |
transparent |
soluble |
|
volume |
insoluble |
non-lustrous |
|
mass |
opaque |
matter |
|
Word |
Meaning |
|
Lustrous |
Shiny or glossy; having a smooth, reflective surface that shines. |
|
Non-lustrous |
Not shiny; dull in appearance. |
|
Transparent |
A material that allows light to pass through completely (you can see through it). |
|
Opaque |
A material that does not allow light to pass through (you cannot see through it). |
|
Soluble |
A substance that can dissolve in a liquid (usually water). |
|
Insoluble |
A substance that cannot dissolve in a liquid. |
|
Volume |
The amount of space an object or substance occupies. |
|
Mass |
The amount of matter in an object; often measured in grams or kilograms. |
|
Matter |
Anything that has mass and takes up space; everything around us is made of matter. |
Answer
Some suggestions for organising kitchen edibles in a better way are:
Answer
|
(i) Matter |
(b) Occupies space and has mass |
|
(ii) Soluble |
(d) Mixes completely in water |
|
(iii) Transparent |
(a) Objects can be seen clearly through it |
|
(iv) Lustre |
(c) Shiny surface |
Answer
Containers used to store materials in shops and at home are often transparent to make it easy to identify the contents inside the containers.
(i) Wood is translucent while glass is opaque. [ ]
(ii) Aluminium foil has lustre while an eraser does not. [ ]
(iii) Sugar dissolves in water whereas sawdust does not. [ ]
(iv) An apple is a matter because it occupies no space and has mass. [ ]
Answer
(i) Wood is translucent while glass is opaque. False [F]
Correct Statement: Wood is opaque while glass is translucent.
(ii) Aluminium foil has lustre while an eraser does not. True [T]
(iii) Sugar dissolves in water whereas sawdust does not. True [T]
(iv) An apple is a matter because it occupies no space and has mass. False [F]
Correct Statement: An apple is a matter as it occupies space and has mass.
(i) Hardness (does not bend or shake on sitting even after long use).
(ii) Lightweight (easy to lift or to take from one place to another).
(iii) Does not feel very cold when sitting during winters.
(iv) Can be cleaned regularly and made to look new even after long use.
Answer
(i) Iron, Cement, Stones.
(ii) Plastic, Bamboo.
(iii) Wood and bamboo chairs does not feel very cold when sitting during winters.
(iv) Plastic and iron chairs can be cleaned regularly and made to look new even after long use.
(i) food waste,
(ii) broken glass and
(iii) wastepaper.
Which materials will you choose for containers of these types of waste? What properties of materials do you need to think of?
Answer
(i) Food waste: Plastic or metal containers are ideal for storing food waste because they are durable, resistant to corrosion and easy to clean.
(ii) Broken glass: Metal or hard plastic containers should be used for collecting broken glass due to their durability and toughness.
(iii) Wastepaper: Light weight plastic or cardboard containers work well for collecting wastepaper.
Choose the most appropriate option:
(i) transparent, opaque
(ii) translucent, transparent
(iii) opaque, translucent
(iv) transparent, translucent
Answer
(i) transparent, opaque
Air is all around us but does not hinder us from seeing each other. Whereas, if a wooden door comes in between, we cannot see each other. It is because air is transparent and the wooden door is opaque.
Answer
Material X is hard because it retains its shape under pressure and is likely a solid that dissolves in water.
Material Y is soft because it changes shape easily when pressed and it does not dissolve in water.
(a) I have lustre. ______
(b) I can be easily compressed. ______
(c) I am hard and soluble in water. ______
(d) You cannot see clearly through me. ______
(e) I have mass and volume but you cannot see me. ______
(ii) Make your own ‘Who am I?’ ______
Answer
(i) Identification on the basis of properties:
(a) I have a lustre. Metal
(b) I can be easily compressed. Gas
(c) I am hard and soluble in water. Salt
(d) You cannot see clearly through me. Translucent objects
(e) I have mass and volume but you cannot see me. Air
(ii) Here's my own "Who am I?"
(a) I am a solid but changes into a liquid at room temperature.
(b) I am poisonous and can cause health hazards if inhaled.
(c) I have a metallic lustre and am used in thermometers.
Who am I? → Mercury.
Make any two pairs of materials where one material is soluble in the other. Now, make two pairs of materials where one material remains insoluble in the other material.
Answer
Two pairs of materials where one material is soluble in the other.
Two pairs of materials where one material remains insoluble in the other material.