MATERIALS AROUND US : Class 6 : Science
1. Introduction
The world around us is made up of different materials – wood, plastic, metal, glass, rubber, cotton, etc.
Different objects are made from different materials depending on their properties and uses.
2. Properties of Materials
Appearance – shiny (metals) or dull (wood, plastic).
Hardness – some are hard (iron, stone), some are soft (cotton, rubber).
Solubility – substances may dissolve in water (salt, sugar) or not dissolve (sand, chalk).
Transparency –
Transparent: allow light (glass, water).
Translucent: partial light (oiled paper, frosted glass).
Opaque: do not allow light (wood, metal).
Floatation – some materials float on water (plastic, wood), some sink (stone, metal).
Conductivity –
Good conductors: allow heat/electricity (metals).
Poor conductors: do not allow heat/electricity (wood, plastic).
3. Grouping of Materials
Materials are grouped for easy study and convenient use.
Example: Soluble/insoluble, Hard/soft, Transparent/opaque, Conductors/insulators.
4. Uses of Materials
Choice of material depends on properties.
Glass for windows (transparent).
Metal for cooking vessels (conducts heat).
Wood/plastic for handles (poor conductor of heat).
SHORT QUESTION ANSWERS (1 MARK EACH)
Q: What is the world around us made of?
A: The world is made of different materials like wood, metal, plastic, glass, etc.
Q: Give one example of a natural material.
A: Cotton.
Q: Give one example of a man-made material.
A: Plastic.
Q: Name one object made from wood.
A: Chair.
Q: Why are different objects made from different materials?
A: Because materials have different properties and uses.
Q: Name one shiny material.
A: Gold.
Q: Name one dull material.
A: Wood.
Q: Which material is hard – iron or rubber?
A: Iron.
Q: Which material is soft – cotton or stone?
A: Cotton.
Q: Name one substance that dissolves in water.
A: Sugar.
Q: Name one substance that does not dissolve in water.
A: Sand.
Q: Give an example of a transparent material.
A: Glass.
Q: Give an example of an opaque material.
A: Wood.
Q: Give an example of a translucent material.
A: Oiled paper.
Q: Which type of material allows all light to pass through?
A: Transparent material.
Q: Which type of material does not allow any light to pass through?
A: Opaque material.
Q: Which type of material allows partial light to pass through?
A: Translucent material.
Q: Name one material that floats on water.
A: Wood.
Q: Name one material that sinks in water.
A: Stone.
Q: Name one good conductor of heat.
A: Copper.
Q: Name one poor conductor of heat.
A: Plastic.
Q: Name one good conductor of electricity.
A: Aluminium.
Q: Name one poor conductor of electricity.
A: Rubber.
Q: Why do we group materials?
A: To study and use them easily.
Q: How can materials be grouped based on solubility?
A: Soluble and insoluble materials.
Q: How can materials be grouped based on appearance?
A: Shiny and dull materials.
Q: How can materials be grouped based on transparency?
A: Transparent, translucent, and opaque materials.
Q: How can materials be grouped based on hardness?
A: Hard and soft materials.
Q: How can materials be grouped based on conductivity?
A: Conductors and insulators.
Q: Which group does salt belong to based on solubility?
A: Soluble.
Q: Which group does chalk belong to based on solubility?
A: Insoluble.
Q: Which group does glass belong to based on transparency?
A: Transparent.
Q: Which group does wood belong to based on transparency?
A: Opaque.
Q: Which group does butter paper belong to based on transparency?
A: Translucent.
Q: Why is glass used to make windows?
A: Because it is transparent.
Q: Why are metals used for cooking vessels?
A: Because they conduct heat.
Q: Why are plastic and wood used for handles of cooking pans?
A: Because they are poor conductors of heat.
Q: Why is cotton used for making clothes?
A: Because it is soft and comfortable.
Q: Why is rubber used to cover electric wires?
A: Because it is an insulator.
Q: Why is steel used to make tools?
A: Because it is hard and strong.
LONG QUESTION ANSWERS
Q: What are materials? Give examples of natural and man-made materials.
A: Materials are substances from which things are made.
Natural materials: Wood, cotton, clay, wool.
Man-made materials: Plastic, glass, nylon, steel.
Q: Why are objects made of different materials? Explain with examples.
A: Objects are made of different materials depending on their properties and uses.
Example: A chair is made of wood (hard and strong), a bottle is made of glass (transparent), clothes are made of cotton (soft and comfortable).
Q: Differentiate between natural and synthetic materials with two examples each.
A:Natural materials: Found in nature (wood, cotton).
Synthetic materials: Made by humans (plastic, nylon).
Q: Write about the appearance of materials. Give examples of shiny and dull materials.
A: Some materials are shiny like gold, silver, aluminium. Others are dull like wood, clay, rubber. Shiny objects are often used in decoration and jewelry.
Q: What is the difference between hard and soft materials? Give two examples each.
A:Hard materials: Difficult to compress or cut (iron, steel).
Soft materials: Can be easily compressed (cotton, rubber).
Q: Explain soluble and insoluble materials with examples.
A:Soluble: Substances that dissolve in water (salt, sugar).
Insoluble: Substances that do not dissolve in water (sand, chalk).
Q: Explain transparent, translucent, and opaque materials with examples.
A:Transparent: Allow all light to pass (glass, water).
Translucent: Allow partial light to pass (butter paper, oiled paper).
Opaque: Do not allow light to pass (wood, stone).
Q: Write the differences between conductors and insulators. Give examples.
A:Conductors: Materials that allow heat/electricity to pass (copper, aluminium).
Insulators: Do not allow heat/electricity to pass (plastic, rubber).
Q: Why do some materials float on water while others sink? Give examples.
A: Materials lighter than water (like wood, plastic ball) float, while heavier materials (like stone, iron) sink.
Q: Write the importance of studying the properties of materials.
A: Knowing properties helps us select the right material for use.
Example: Glass for windows (transparent), metal for utensils (conducts heat), plastic for wire covers (insulator).
Q: Why do we group materials?
A: Grouping helps in studying and using materials easily. Example: Metals are grouped together because they are hard, shiny, and conduct heat.
Q: How are materials grouped based on appearance? Give examples.
A:Shiny: Gold, aluminium.
Dull: Wood, clay.
Q: How are materials grouped based on hardness? Give examples.
A:Hard: Stone, iron.
Soft: Cotton, rubber.
Q: How are materials grouped based on solubility? Give examples.
A:Soluble: Salt, sugar.
Insoluble: Sand, chalk.
Q: How are materials grouped based on transparency? Give examples.
A:Transparent: Glass.
Translucent: Oiled paper.
Opaque: Wood.
Q: How are materials grouped based on conductivity? Give examples.
A:Conductors: Iron, copper.
Insulators: Rubber, plastic.
Q: Write examples of grouping of materials in our daily life.
A: Clothes (cotton, wool), utensils (steel, aluminium), furniture (wood, plastic).
Q: Why is glass used to make windows?
A: Glass is transparent, so it allows light to pass through while protecting us from dust, wind, and rain.
Q: Why are metals used for making utensils?
A: Metals like copper and aluminium are good conductors of heat and strong, so they are used for making utensils.
Q: Why are handles of cooking pans made of wood or plastic?
A: Because they are poor conductors of heat and prevent burns while holding pans.
Q: Why is cotton used for making clothes?
A: Cotton is soft, light, and allows air to pass, keeping us cool and comfortable.
Q: Why is wool used for making sweaters?
A: Wool is a poor conductor of heat and keeps our body warm in winter.
Q: Why is plastic widely used?
A: Plastic is cheap, light, strong, waterproof, and does not rust.
Q: Why is rubber used to cover electric wires?
A: Rubber is an insulator and prevents electric shocks.
Q: Why is steel used to make tools and machines?
A: Steel is hard, strong, and durable, so it is used for making machines, tools, and vehicles.
Q: Why is wood used for making furniture?
A: Wood is strong, easily available, and can be cut into shapes, so it is used for furniture.
Q: Why is aluminium used in making airplanes?
A: Aluminium is light in weight and strong, so it is used in airplanes.
Q: Why are gold and silver used in making jewelry?
A: Because they are shiny, attractive, and do not rust easily.
Q: Why is copper used for making electrical wires?
A: Copper is a good conductor of electricity and can be stretched into thin wires.
Q: Why are plastics not suitable for cooking utensils?
A: Because plastic is a poor conductor of heat and can melt on heating.
MCQS –CHOOSE THE CORRECT OPTION:
Which of the following is a transparent material?
a) Wood
b) Glass
c) Stone
d) Plastic
Answer: b) Glass
Which material is soft?
a) Iron
b) Stone
c) Cotton
d) Aluminium
Answer: c) Cotton
Which of these will dissolve in water?
a) Sand
b) Chalk powder
c) Sugar
d) Stone
Answer: c) Sugar
Materials that do not allow light to pass through them are called:
a) Transparent
b) Translucent
c) Opaque
d) Conductors
Answer: c) Opaque
Which of the following floats on water?
a) Iron nail
b) Stone
c) Plastic ball
d) Coin
Answer: c) Plastic ball
Metals are generally:
a) Dull and soft
b) Shiny and hard
c) Soft and soluble
d) Opaque and soluble
Answer: b) Shiny and hard
Which material is used for making handles of cooking utensils?
a) Iron
b) Plastic
c) Copper
d) Aluminium
Answer: b) Plastic
Which of these is a good conductor of heat?
a) Wood
b) Plastic
c) Iron
d) Rubber
Answer: c) Iron
Which of the following is an insulator?
a) Aluminium
b) Copper
c) Wood
d) Iron
Answer: c) Wood
Which of these is translucent?
a) Clear glass
b) Oiled paper
c) Wood
d) Metal sheet
Answer: b) Oiled paper
The property of a material to allow electricity to pass through is called:
a) Transparency
b) Conductivity
c) Solubility
d) Hardness
Answer: b) Conductivity
Which of these is not soluble in water?
a) Salt
b) Sand
c) Sugar
d) Lemon juice
Answer: b) Sand
Which of the following is used to make window panes?
a) Wood
b) Glass
c) Rubber
d) Plastic
Answer: b) Glass
Which material is best for making cooking vessels?
a) Copper
b) Rubber
c) Wood
d) Plastic
Answer: a) Copper
Why is plastic not used for cooking?
a) It is too expensive
b) It is a poor conductor of heat
c) It is transparent
d) It is shiny
Answer: b) It is a poor conductor of heat
Which of the following is a transparent material?
a) Wood
b) Glass
c) Stone
d) Plastic
Answer: b) Glass
Which material is soft?
a) Iron
b) Stone
c) Cotton
d) Aluminium
Answer: c) Cotton
Which of these will dissolve in water?
a) Sand
b) Chalk powder
c) Sugar
d) Stone
Answer: c) Sugar
Materials that do not allow light to pass through them are called:
a) Transparent
b) Translucent
c) Opaque
d) Conductors
Answer: c) Opaque
Which of the following floats on water?
a) Iron nail
b) Stone
c) Plastic ball
d) Coin
Answer: c) Plastic ball
Metals are generally:
a) Dull and soft
b) Shiny and hard
c) Soft and soluble
d) Opaque and soluble
Answer: b) Shiny and hard
Which material is used for making handles of cooking utensils?
a) Iron
b) Plastic
c) Copper
d) Aluminium
Answer: b) Plastic
Which of these is a good conductor of heat?
a) Wood
b) Plastic
c) Iron
d) Rubber
Answer: c) Iron
Which of the following is an insulator?
a) Aluminium
b) Copper
c) Wood
d) Iron
Answer: c) Wood
Which of these is translucent?
a) Clear glass
b) Oiled paper
c) Wood
d) Metal sheet
Answer: b) Oiled paper
The property of a material to allow electricity to pass through is called:
a) Transparency
b) Conductivity
c) Solubility
d) Hardness
Answer: b) Conductivity
Which of these is not soluble in water?
a) Salt
b) Sand
c) Sugar
d) Lemon juice
Answer: b) Sand
Which of the following is used to make window panes?
a) Wood
b) Glass
c) Rubber
d) Plastic
Answer: b) Glass
Which material is best for making cooking vessels?
a) Copper
b) Rubber
c) Wood
d) Plastic
Answer: a) Copper
Why is plastic not used for cooking?
a) It is too expensive
b) It is a poor conductor of heat
c) It is transparent
d) It is shiny
Answer: b) It is a poor conductor of heat
Which of these is a natural material?
a) Nylon
b) Wool
c) Plastic
d) Polyester
Answer: b) Wool
Which of the following is man-made?
a) Cotton
b) Wool
c) Nylon
d) Silk
Answer: c) Nylon
Which material is used to make electric wires?
a) Wood
b) Rubber
c) Copper
d) Plastic
Answer: c) Copper
The property of a material to allow light to pass fully through is:
a) Opaque
b) Translucent
c) Transparent
d) Conductive
Answer: c) Transparent
Which of the following is flexible?
a) Stone
b) Paper
c) Metal rod
d) Glass
Answer: b) Paper
Which is heavier than water and sinks?
a) Oil
b) Wood
c) Stone
d) Plastic
Answer: c) Stone
Which of these is a non-metal?
a) Copper
b) Aluminium
c) Wood
d) Iron
Answer: c) Wood
Which of these is not a property of metals?
a) Shiny
b) Hard
c) Good conductor
d) Transparent
Answer: d) Transparent
Which is the best conductor of electricity?
a) Plastic
b) Glass
c) Copper
d) Wood
Answer: c) Copper
Which of these is not used to make clothes?
a) Cotton
b) Jute
c) Wool
d) Stone
Answer: d) Stone
Which of the following is a hard material?
a) Rubber
b) Wood
c) Stone
d) Cotton
Answer: c) Stone
Which of the following is ductile (can be drawn into wires)?
a) Stone
b) Copper
c) Wood
d) Plastic
Answer: b) Copper
Which of the following is malleable (can be beaten into sheets)?
a) Iron
b) Stone
c) Glass
d) Wood
Answer: a) Iron
Which of the following is not a metal?
a) Iron
b) Aluminium
c) Copper
d) Plastic
Answer: d) Plastic
Which of these can be recycled easily?
a) Plastic
b) Glass
c) Rubber
d) Wood
Answer: b) Glass
Which is the lightest material among the following?
a) Cotton
b) Iron
c) Copper
d) Stone
Answer: a) Cotton
Which of these is waterproof?
a) Paper
b) Cloth
c) Plastic
d) Cotton
Answer: c) Plastic
Which property is tested when we try to bend a material?
a) Transparency
b) Hardness
c) Flexibility
d) Solubility
Answer: c) Flexibility
Which of the following is used for making furniture?
a) Wool
b) Wood
c) Glass
d) Cotton
Answer: b) Wood
Which of these is both flexible and waterproof?
a) Stone
b) Plastic
c) Glass
d) Metal
Answer: b) Plastic
