Extra 20 important long questions and answers from the CBSE Class 6 Science chapter:4 "Sorting Materials into Groups."
1. Why do we need to sort materials into groups?
✅ Answer:
Sorting materials helps in their
easy identification
and use.
It helps in
organizing things
properly.
It makes storage and handling
more efficient.
Grouping helps in understanding
properties of materials.
It is useful in
scientific studies
and experiments.
2. What are the different properties used to classify materials?
✅ Answer:
Appearance
(shiny, dull, smooth, rough).
Hardness
(hard, soft).
Solubility
(soluble, insoluble).
Transparency
(transparent, translucent, opaque).
Conductivity
(conductors, insulators).
Floating and sinking
in water.
3. What are transparent, translucent, and opaque materials? Give examples.
✅ Answer:
Transparent materials
allow light to pass completely (e.g., glass, clean water).
Translucent materials
allow some light to pass (e.g., butter paper, frosted glass).
Opaque materials
do not allow light to pass (e.g., wood, metal).
4. How does the hardness of a material help in its usage?
✅ Answer:
Hard materials
like iron and stone are used for construction.
Soft materials
like cotton and rubber are used for making clothes and cushions.
Hard materials are
durable
and long-lasting.
Soft materials are
comfortable
for everyday use.
5. What is solubility? Name some substances that are soluble and insoluble in water.
✅ Answer:
Solubility is the ability of a substance to
dissolve in water.
Soluble substances:
Salt, sugar, lemon juice.
Insoluble substances:
Sand, oil, chalk powder.
Solubility helps in making
solutions
like saltwater and juices.
6. What are good conductors and poor conductors of heat? Give examples.
✅ Answer:
Good conductors
allow heat to pass through (e.g., iron, aluminium).
Poor conductors
(insulators) do not allow heat to pass (e.g., wood, plastic).
Cooking utensils are made of
metals
because they conduct heat.
Handles of utensils are made of
wood or plastic
to prevent burns.
7. Why is iron used for making bridges and buildings?
✅ Answer:
Iron is
strong and durable.
It can bear
heavy loads and pressure.
It is
malleable
and can be shaped into structures.
It provides
stability and support
to buildings.
It is
cheaper and widely available.
8. What is the importance of grouping objects in daily life?
✅ Answer:
It helps in
quick identification
of objects.
It makes
storage and arrangement easier.
It helps in
scientific studies and experiments.
It helps in
waste segregation
(biodegradable and non-biodegradable).
9. What are magnetic and non-magnetic materials? Give examples.
✅ Answer:
Magnetic materials
are attracted by magnets (e.g., iron, cobalt, nickel).
Non-magnetic materials
are not attracted by magnets (e.g., wood, plastic, glass).
Magnetic materials are used in making
compasses, motors, and fridge doors.
10. Why are metals shiny while wood is dull?
✅ Answer:
Metals have a property called
lustre,
which makes them shiny.
They reflect light, giving them a polished look.
Wood does not have this property, so it appears dull.
11. What are the advantages of using transparent materials in daily life?
✅ Answer:
Transparent materials
allow light to pass
through them, making them useful for windows.
They help in
visibility and clarity,
like in spectacles and glass doors.
Transparent plastic bottles help us
see the amount of liquid left inside.
Used in
laboratory equipment
like test tubes and beakers for clear observation.
Useful in
solar panels
to allow sunlight to pass and generate energy.
Transparent materials like
cellophane wraps
help in food packaging to check freshness.
12. Why is plastic widely used in making household and industrial products?
✅ Answer:
Plastic is
lightweight
and easy to carry.
It is
waterproof
and protects items from moisture.
It is
non-reactive
and does not rust or decay.
Plastics are
flexible
and can be
moulded
into different shapes.
They are
insulators
, making them useful for covering electrical wires.
Plastics are
cheap and durable
, making them widely used in industries.
13. How does the property of materials affect their usage? Give examples.
✅ Answer:
Hard materials
(iron, stone) are used in construction for strength.
Soft materials
(cotton, wool) are used for making clothes and pillows.
Transparent materials
(glass) are used for making windows and spectacles.
Waterproof materials
(plastic, rubber) are used for making raincoats and pipes.
Magnetic materials
(iron, nickel) are used in making compasses and machines.
Soluble materials
(sugar, salt) are used in cooking and medicine preparation.
14. How can we test whether a material is a conductor or an insulator of electricity?
✅ Answer:
Take a
circuit with a bulb and a battery.
Connect the material to be tested in the circuit.
If the bulb
glows
, the material is a
conductor
(e.g., copper, iron).
If the bulb
does not glow
, the material is an
insulator
(e.g., wood, rubber).
Conductors allow electricity to pass, making them useful in electrical wiring.
Insulators block electricity and are used in making switches and wire coverings.
15. Why do we use different materials for making utensils?
✅ Answer:
Metals like aluminium and stainless steel
are used because they conduct heat well.
Non-stick cookware
is made using
Teflon
, which prevents food from sticking.
Plastic and glass
containers are used for storing food as they do not react with food.
Clay and earthen pots
are used as they keep water cool naturally.
Copper vessels
are used because they have antibacterial properties.
Wooden ladles
are used for stirring food as they do not conduct heat.
16. What are the uses of materials that float on water?
✅ Answer:
Wood
is used to make boats and ships because it floats.
Plastic bottles
are used in life jackets for buoyancy.
Cork
is used in fishing nets and bottle stoppers.
Thermocol
is used in packaging fragile materials as it is lightweight.
Rubber tubes and rafts
help in water rescue operations.
Leaves and dry twigs
float and are used by some aquatic insects to stay above water.
17. How does the ability to absorb or repel water help in daily life?
✅ Answer:
Clothes like raincoats
are made from waterproof materials to keep us dry.
Towels
are made from cotton, which absorbs water.
Umbrellas
are made of waterproof fabrics to protect from rain.
Soil absorbs rainwater
, helping plants grow.
Clay absorbs water
, making it useful in pottery.
Waterproof paints
protect walls from water damage.
18. How is the property of flexibility used in making objects?
✅ Answer:
Rubber bands
are flexible and can stretch without breaking.
Plastic pipes
are flexible, making them easy to bend and install.
Fabric materials
like cotton and wool are flexible and used in making clothes.
Rubber and synthetic leather
are used in making shoes as they bend with movement.
Flexible wires
are used in electronic devices for easy connection.
Silicone materials
are used in bakeware as they can bend without breaking.
19. Why is glass used for making laboratory equipment?
✅ Answer:
Glass is
transparent
, allowing clear observation of reactions.
It is
non-reactive
, so it does not react with chemicals.
It can withstand
high temperatures
, making it suitable for heating substances.
It is
easy to clean
and sterilize, maintaining hygiene.
Glass does not absorb liquids, preventing contamination.
It is
durable
and can be shaped into test tubes, beakers, and measuring cylinders.
20. How is the classification of materials helpful in waste management?
✅ Answer:
Biodegradable waste
(food scraps, paper) decomposes and can be composted.
Non-biodegradable waste
(plastic, metal) does not decompose and should be recycled.
Segregation of waste
helps in better disposal and reduces pollution.
Glass and metal recycling
helps
in conserving natural resources.
Plastic waste management
reduces environmental hazards.
Proper waste classification makes cities cleaner and reduces landfill waste.
