Chapter 10 of 12
Chapter 10: This World of Things
Exploring Everyday Materials: Wood, Clay, Metal, Glass, Fabric, and Their Distinct Properties | CBSE Session 2026–27
Core Pedagogical Competencies & Concepts
- Classification of materials based on origin: Natural (wood, cotton, stone) and human-made (plastic, glass, nylon).
- Properties of materials: Hard vs soft, rough vs smooth, opaque vs transparent, waterproof vs absorbent.
- Matching properties to practical uses: Why umbrellas use waterproof fabric and cooking pots use metals.
- The lifecycle of materials: Mining, crafting, usage, wear and tear, and disposal.
All Textbook Exercises & In-Text Tasks (17 Questions)
100% Complete Ingestion
Q1
Material Properties & Suitability
Why are cooking frying pans made of metal (like iron or aluminum) while their handles are made of wood or Bakelite plastic?
[3 Marks]
✅ Step-by-Step Solution & Working
This design relies on heat conduction properties:
1. Metal Body (Pan): Metals are excellent conductors of heat. They absorb heat rapidly from the stove flame and distribute it evenly across the base to cook food quickly.
2. Wood / Bakelite Handle: Wood and Bakelite are bad conductors of heat (thermal insulators). They remain cool even when the pan is piping hot, allowing us to hold the pan safely without burning our hands.
1. Metal Body (Pan): Metals are excellent conductors of heat. They absorb heat rapidly from the stove flame and distribute it evenly across the base to cook food quickly.
2. Wood / Bakelite Handle: Wood and Bakelite are bad conductors of heat (thermal insulators). They remain cool even when the pan is piping hot, allowing us to hold the pan safely without burning our hands.
CBSE Step-by-Step Marking Scheme
Explanation of metal as a good thermal conductor
1.5 Marks
Explanation of wood/Bakelite as an insulator for burn safety
1.5 Marks
Q2
Transparency & Light Properties
Distinguish between transparent, translucent, and opaque materials with two practical household examples of each.
[3 Marks]
✅ Step-by-Step Solution & Working
• Transparent: Materials that allow light to pass through completely, enabling us to see clearly across them (e.g., Clear window glass, pure drinking water).
• Translucent: Materials that allow only partial light to pass through, creating blurred or hazy vision (e.g., Butter paper, frosted bathroom glass).
• Opaque: Materials that block light completely, casting a dark shadow and preventing vision across them (e.g., Wooden door, brick wall, metal plate).
• Translucent: Materials that allow only partial light to pass through, creating blurred or hazy vision (e.g., Butter paper, frosted bathroom glass).
• Opaque: Materials that block light completely, casting a dark shadow and preventing vision across them (e.g., Wooden door, brick wall, metal plate).
CBSE Step-by-Step Marking Scheme
Clear physical definitions of transparent, translucent, and opaque
1.5 Marks
Accurate household examples for each category
1.5 Marks
Q3
Absorbency & Waterproofing
Why do we wear cotton clothes in hot summers and synthetic raincoats in monsoons?
[2 Marks]
✅ Step-by-Step Solution & Working
Cotton is a natural porous fiber that absorbs body sweat easily and allows air circulation to keep our skin cool through evaporation. Synthetic raincoat fabrics (like rubberized nylon or PVC) are completely waterproof and non-porous, preventing rain droplets from soaking through to our clothes.
CBSE Step-by-Step Marking Scheme
Cotton's sweat absorption and breathability
1 Mark
Raincoat fabric's waterproof barrier property
1 Mark
Q4
Material Science • Everyday Properties
Match each material with its characteristic property:
• Glass: [Transparent and breaks easily, Flexible and waterproof, Hard and can rust, Soft and absorbs water]
• Rubber: [Transparent and breaks easily, Flexible and waterproof, Hard and can rust, Soft and absorbs water]
• Iron: [Transparent and breaks easily, Flexible and waterproof, Hard and can rust, Soft and absorbs water]
• Cotton cloth: [Transparent and breaks easily, Flexible and waterproof, Hard and can rust, Soft and absorbs water]
[4 Marks]
• Glass: [Transparent and breaks easily, Flexible and waterproof, Hard and can rust, Soft and absorbs water]
• Rubber: [Transparent and breaks easily, Flexible and waterproof, Hard and can rust, Soft and absorbs water]
• Iron: [Transparent and breaks easily, Flexible and waterproof, Hard and can rust, Soft and absorbs water]
• Cotton cloth: [Transparent and breaks easily, Flexible and waterproof, Hard and can rust, Soft and absorbs water]
✅ Step-by-Step Solution & Working
Material Properties:
• Glass: Transparent and brittle (breaks easily)
• Rubber: Flexible, elastic, and waterproof
• Iron: Hard, strong, and can rust if left wet
• Cotton cloth: Soft, breathable, and absorbs water
• Glass: Transparent and brittle (breaks easily)
• Rubber: Flexible, elastic, and waterproof
• Iron: Hard, strong, and can rust if left wet
• Cotton cloth: Soft, breathable, and absorbs water
CBSE Step-by-Step Marking Scheme
Correct matching for all 4 material properties
4.0 M
Q5
Float or Sink Experiment • Density
In an experiment testing buoyancy in a bucket of water:
(a) Why does an iron needle sink, but a hollow iron bowl float?
(b) Why does a dry sponge float initially but sink after some time?
[3 Marks]
(a) Why does an iron needle sink, but a hollow iron bowl float?
(b) Why does a dry sponge float initially but sink after some time?
✅ Step-by-Step Solution & Working
Buoyancy Physics:
(a) Iron Needle vs Bowl:
• An iron needle is solid and dense, displacing very little water, so it sinks.
• A hollow iron bowl contains trapped air inside its curved shape, which makes its overall weight lighter than the large volume of water it pushes aside, allowing it to float.
(b) Sponge Behavior:
• A dry sponge has tiny open pores filled with air, making it very light so it floats.
• As water fills all the pores, displacing the air, the sponge becomes heavy and eventually sinks.
(a) Iron Needle vs Bowl:
• An iron needle is solid and dense, displacing very little water, so it sinks.
• A hollow iron bowl contains trapped air inside its curved shape, which makes its overall weight lighter than the large volume of water it pushes aside, allowing it to float.
(b) Sponge Behavior:
• A dry sponge has tiny open pores filled with air, making it very light so it floats.
• As water fills all the pores, displacing the air, the sponge becomes heavy and eventually sinks.
CBSE Step-by-Step Marking Scheme
Water displacement and air volume explained for bowl
1.5 M
Pore air displacement explained for wet sponge
1.5 M
Q6
Magnetic Properties • Materials Test
Which of the following items will be attracted to a magnet?
Iron paper clip, Wooden pencil, Steel safety pin, Plastic eraser, Copper coin.
[3 Marks]
Iron paper clip, Wooden pencil, Steel safety pin, Plastic eraser, Copper coin.
✅ Step-by-Step Solution & Working
Magnetic Test:
• Attracted to Magnet: Iron paper clip, Steel safety pin (contain iron/steel).
• Not Attracted: Wooden pencil, Plastic eraser, Copper coin (non-magnetic materials).
• Attracted to Magnet: Iron paper clip, Steel safety pin (contain iron/steel).
• Not Attracted: Wooden pencil, Plastic eraser, Copper coin (non-magnetic materials).
CBSE Step-by-Step Marking Scheme
Correct magnetic items identified
1.5 M
Correct non-magnetic items identified
1.5 M
Q7
Natural vs Synthetic Materials
Differentiate between natural materials and synthetic (man-made) materials with one example of each.
[2 Marks]
✅ Step-by-Step Solution & Working
Definitions & Examples:
• Natural Material: Obtained directly from nature (plants, animals, earth) without chemical modification (e.g., Wood, Cotton, Wool, Clay).
• Synthetic Material: Created artificially by humans in factories through chemical processing (e.g., Plastic, Nylon, Polythene).
• Natural Material: Obtained directly from nature (plants, animals, earth) without chemical modification (e.g., Wood, Cotton, Wool, Clay).
• Synthetic Material: Created artificially by humans in factories through chemical processing (e.g., Plastic, Nylon, Polythene).
CBSE Step-by-Step Marking Scheme
Clear contrast with valid examples
2.0 M
Q8
Find Out & Write • Environmental Observation
In Chapter 10 ('This World of Things'), what key natural elements or community roles are highlighted? List three observations.
[3 Marks]
✅ Step-by-Step Solution & Working
Observations:
1. Interdependence: Plants, animals, and humans depend closely on each other for food, oxygen, and shelter.
2. Community Helpers: People in our neighbourhood perform essential services (farmers, sanitation workers, doctors, teachers).
3. Resource Conservation: Water, soil, and clean air are precious gifts that must not be polluted or wasted.
1. Interdependence: Plants, animals, and humans depend closely on each other for food, oxygen, and shelter.
2. Community Helpers: People in our neighbourhood perform essential services (farmers, sanitation workers, doctors, teachers).
3. Resource Conservation: Water, soil, and clean air are precious gifts that must not be polluted or wasted.
CBSE Step-by-Step Marking Scheme
Interdependence observed
1 M
Community helpers recognized
1 M
Conservation awareness
1 M
Q9
Discuss & Share • Classroom Activity
Discuss with your classmates: How does the change of seasons impact the food we eat, clothes we wear, and activities in 'This World of Things'?
[3 Marks]
✅ Step-by-Step Solution & Working
Seasonal Impact:
• Summer: We wear light cotton clothes, drink lots of water and fresh juices, and eat fruits like mangoes and watermelons.
• Winter: We wear warm woollens, enjoy hot soups and nuts, and sit in the sun.
• Monsoon: We use umbrellas and raincoats, and enjoy hot pakoras while taking care to avoid stagnant water.
• Summer: We wear light cotton clothes, drink lots of water and fresh juices, and eat fruits like mangoes and watermelons.
• Winter: We wear warm woollens, enjoy hot soups and nuts, and sit in the sun.
• Monsoon: We use umbrellas and raincoats, and enjoy hot pakoras while taking care to avoid stagnant water.
CBSE Step-by-Step Marking Scheme
Summer adaptations
1 M
Winter adaptations
1 M
Monsoon adaptations
1 M
Q10
Think & Reflect • Environmental Care
What simple daily action can you and your family take to reduce waste and protect nature as suggested in 'This World of Things'?
[2 Marks]
✅ Step-by-Step Solution & Working
Daily Actions:
1. Segregate Waste: Keep green dustbins for wet biodegradable kitchen waste and blue dustbins for dry recyclable plastic/paper.
2. Avoid Single-Use Plastic: Carry cloth bags for vegetable shopping and refill reusable steel water bottles.
1. Segregate Waste: Keep green dustbins for wet biodegradable kitchen waste and blue dustbins for dry recyclable plastic/paper.
2. Avoid Single-Use Plastic: Carry cloth bags for vegetable shopping and refill reusable steel water bottles.
CBSE Step-by-Step Marking Scheme
Waste segregation explained
1 M
Avoiding single-use plastics
1 M
Q11
Activity • Classification & Grouping
Classify the following items into Living Things and Non-Living Things: Neem tree, School bus, Butterfly, River stone, Honeybee, Wooden table.
[3 Marks]
✅ Step-by-Step Solution & Working
Classification:
• Living Things: Neem tree, Butterfly, Honeybee (they breathe, grow, and reproduce).
• Non-Living Things: School bus, River stone, Wooden table (they do not grow or breathe).
• Living Things: Neem tree, Butterfly, Honeybee (they breathe, grow, and reproduce).
• Non-Living Things: School bus, River stone, Wooden table (they do not grow or breathe).
CBSE Step-by-Step Marking Scheme
Living things identified correctly
1.5 M
Non-living things identified correctly
1.5 M
Q12
Field Exploration • Plants in Neighbourhood
Look closely at leaves of different plants around your school. How do they differ from one another in shape, colour, and texture?
[3 Marks]
✅ Step-by-Step Solution & Working
Leaf Observations:
• Shape: Banana leaves are broad and long, peepal leaves have a pointed tip, and pine needles are thin and pointy.
• Colour: Leaves vary from light yellow-green to dark emerald green, and some crotons have red or purple spots.
• Texture: Lotus leaves feel waxy, rose leaves feel soft with serrated margins, and hibiscus leaves feel slightly rough.
• Shape: Banana leaves are broad and long, peepal leaves have a pointed tip, and pine needles are thin and pointy.
• Colour: Leaves vary from light yellow-green to dark emerald green, and some crotons have red or purple spots.
• Texture: Lotus leaves feel waxy, rose leaves feel soft with serrated margins, and hibiscus leaves feel slightly rough.
CBSE Step-by-Step Marking Scheme
Difference in shape
1 M
Difference in colour
1 M
Difference in texture
1 M
Q13
Health & Hygiene • Good Habits
Why must we wash our hands with soap before eating and after using the toilet? Describe the correct 6-step method.
[2 Marks]
✅ Step-by-Step Solution & Working
Importance & Method:
• Washing with soap removes invisible disease-causing germs and bacteria.
• Steps: Wet hands, apply soap, rub palms together, wash backs of hands, clean between fingers and under nails, rinse thoroughly under running water, and dry with a clean towel.
• Washing with soap removes invisible disease-causing germs and bacteria.
• Steps: Wet hands, apply soap, rub palms together, wash backs of hands, clean between fingers and under nails, rinse thoroughly under running water, and dry with a clean towel.
CBSE Step-by-Step Marking Scheme
Reason for washing hands
1 M
Steps described
1 M
Q14
Water Conservation • Every Drop Counts
List three practical ways to save drinking water at home and in school.
[3 Marks]
✅ Step-by-Step Solution & Working
Water Saving Ways:
1. Turn off the tap tightly while brushing teeth instead of letting water run.
2. Use a bucket and mug for bathing rather than a shower.
3. Pour leftover water from drinking bottles into plant pots instead of draining it away.
1. Turn off the tap tightly while brushing teeth instead of letting water run.
2. Use a bucket and mug for bathing rather than a shower.
3. Pour leftover water from drinking bottles into plant pots instead of draining it away.
CBSE Step-by-Step Marking Scheme
Three valid water conservation methods
3 M
Q15
Animal Empathy • Coexistence
How can we help birds and stray animals during the hot summer season?
[2 Marks]
✅ Step-by-Step Solution & Working
Helping Summer Animals:
• Place an earthen clay bowl filled with clean fresh water on the terrace, balcony, or under a tree for thirsty birds.
• Keep a bowl of water in the shade outside the house for community dogs and cats.
• Never disturb bird nests or throw stones at sleeping animals.
• Place an earthen clay bowl filled with clean fresh water on the terrace, balcony, or under a tree for thirsty birds.
• Keep a bowl of water in the shade outside the house for community dogs and cats.
• Never disturb bird nests or throw stones at sleeping animals.
CBSE Step-by-Step Marking Scheme
Clay water bowls for birds
1 M
Kind treatment and shade
1 M
Q16
Community Living • Festivals and Food
Name two traditional Indian festivals and describe the special food items prepared and shared during these celebrations.
[2 Marks]
✅ Step-by-Step Solution & Working
Festivals and Traditional Foods:
1. Eid: Families prepare and share sweet Sevaiyan (vermicelli pudding) and biryani with neighbours.
2. Holi: People celebrate spring by sharing traditional Gujiyas and refreshing thandai.
3. Diwali: Families distribute homemade Laddoos, kaju katli, and savoury namkeens.
1. Eid: Families prepare and share sweet Sevaiyan (vermicelli pudding) and biryani with neighbours.
2. Holi: People celebrate spring by sharing traditional Gujiyas and refreshing thandai.
3. Diwali: Families distribute homemade Laddoos, kaju katli, and savoury namkeens.
CBSE Step-by-Step Marking Scheme
Two festivals named with corresponding special food
2 M
Q17
Review Questions • True or False
State True or False:
(a) Plants take in carbon dioxide and give out oxygen during daytime.
(b) Rainwater harvesting means collecting and storing rainwater for future use.
(c) Burning dry leaves and plastic in open air keeps the environment healthy.
[3 Marks]
(a) Plants take in carbon dioxide and give out oxygen during daytime.
(b) Rainwater harvesting means collecting and storing rainwater for future use.
(c) Burning dry leaves and plastic in open air keeps the environment healthy.
✅ Step-by-Step Solution & Working
Answers:
• (a) True: Photosynthesis produces oxygen.
• (b) True: Rainwater harvesting replenishes groundwater.
• (c) False: Burning releases toxic smoke and causes severe air pollution. Dry leaves should be composted into organic manure.
• (a) True: Photosynthesis produces oxygen.
• (b) True: Rainwater harvesting replenishes groundwater.
• (c) False: Burning releases toxic smoke and causes severe air pollution. Dry leaves should be composted into organic manure.
CBSE Step-by-Step Marking Scheme
True, True, False with explanations
3 M
🌟 NEP 2020 Competency-Based Case Study
Sustainable Material Substitution: Moving Beyond Single-Use Plastics
A town council notices that drainage pipes are repeatedly clogged with thin single-use plastic grocery bags, plastic straws, and thermocol plates, causing artificial floods during monsoon rain showers.
Analytical Task: Apply your scientific understanding of material properties to recommend biodegradable, eco-friendly substitutes for plastic bags, cups, and plates.
Evaluation & Model Answer:
Plastic is synthetic, waterproof, and non-biodegradable; it chokes drains and persists in nature for hundreds of years. We can substitute plastic with materials that match functional needs while being completely compostable: (1) Jute and Cotton: Strong, reusable woven fibers for shopping bags. (2) Dried Areca Nut Palm Leaf (Pattal): Naturally pressed sturdy, leak-proof plates for community feasts that biodegrade into rich soil compost within weeks. (3) Terracotta Kulhads: Porous earthenware cups that impart a pleasant earthy aroma and break down safely back into natural clay soil. (4) Paper or Bamboo Straws: Organic plant fibers replacing plastic drinking tubes.
Rubric: Critique of non-biodegradability, specific sustainable replacements (jute, areca palm leaves, clay kulhads), soil biodegradability (4 Marks).