Table of Contents
Extra Questions – Sorting Materials Into Groups
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Objects around us
Question 1.
What do you mean by classification?
Answer:
The act of grouping or sorting together things with similar or contrasting qualities or properties is known as classification.
Question 2.
What is the need for classification?
Answer:
It is necessary to classify for the following reasons:
- Objects’ identification
- Object classification
- locating objects
- recognising similarities and differences between objects
- facilitating and enriching the study of items
Question 3.
Why is mercury used in making thermometers?
Answer:
- At room temperature, mercury is a liquid.
- It is a good heat conductor.
- Because mercury has a lustre, it is simple to read the temperature displayed by the mercury level.
Question 4.
On what basis are the various objects grouped?
Answer:
The following characters can be used to group together distinct objects:
- size
- shape
- colour
- hardness
- solubility in water
- magnetism
- heat conduction
- transparency, and so on.
Question 5.
Why do we need the grouping of objects?
Answer:
Organizing the objects by grouping them makes it easier to arrange them in a logical order. When the objects are grouped together, they are much easier to manage. When objects are grouped, it is much easier to understand their properties. It’s also easier to compare two objects when they’re grouped together.
Question 6.
How does the grouping of objects help the shopkeeper?
Answer:
It is easier to work when objects are well organised. When we go to buy something, the shopkeeper can quickly find it because there are distinct shelves for different items and comparable ones are stored together. He would never be able to find them so fast and simply if he placed them all at random.
Question 7.
Name the various materials from which following things can be made:
Shoes, chair, coins, utensils, clothes.
Answer:
- Shoes: Leather, rubber, plastic, canvas
- Chair: Wood, metal, plastic, concrete
- Coins: Copper, silver, gold
- Utensils: Iron, copper, aluminium
- Clothes: Cotton, wool, silk, rayon, nylon.
Question 8.
Name any four materials that can be used to make school bags.
Answer:
Cloth (of cotton, jute, nylon, etc.), plastic, metal or alloy.
Question 9.
List any three solutions that are used in your home.
Answer:
Salt solution, sugar solution, cold drinks, lime juice, etc.
Question 10.
Why is water important for our body?
Answer:
Water is required by the body because it has the ability to dissolve a wide range of compounds. It is also an important component of our body’s cells.
Properties of materials
Question 1.
List five each opaque and transparent materials.
Answer:
Opaque materials:
- Wood
- Iron
- Cardboard
- Brick
- Gold.
Transparent materials:
- Water
- Glass
- Air
- Cellophine plastic, and
- Fibreglass.
Question 2.
List five objects that are made from transparent materials.
Answer:
- Beaker,
- Test tube,
- Conical flask,
- Glass jug, and
- Glass doors.
Question 3.
List five liquids that are transparent.
Answer:
- Water
- Hydrochloric acid
- Alcohol
- Acetone, and
- Petrol.
Question 4
List five objects that are made from an opaque material.
Answer:
- Books
- Blackboard
- Cardboard
- Wall, and
- Wooden furniture.
Question 5.
Why is water called universal solvent?
Answer:
Water is a universal solvent because of its ability to dissolve a wide range of compounds.
Question 6.
List three liquids that are miscible in water.
Answer:
- Milk
- glycerine, and
- soft drinks.
Question 7.
List three liquids that are immiscible in water.
Answer:
- Edible oil
- kerosene oil, and
- petrol.
Question 8.
State conditions when pure water can lose transparency.
Answer:
When the water cools, it condenses into ice which is not transparent.
Question 9.
List the following substances as soluble and insoluble in water.
Sand, salt, sugar, paint, chilli powder, desi ghee, blotting paper.
Answer:
Water-soluble substances: Salt, sugar.
Water-insoluble substances: Sand, paint, chilli powder, desi ghee, blotting paper.
Question 10.
Show that sugar, common salt and washing soda are soluble while chalk powder, iodine and sand are insoluble in water.
Answer:
Fill six test tubes with roughly half-filled water each. Place them all in a test tube stand. In separate test tubes, put a pinch of each of the six chemicals. Shake vigorously and let aside for a few minutes. Iodine, chalk powder, and sand do not dissolve with common salt, sugar, or washing soda.
Question 11.
Describe a method to prove that water is a transparent material.
Answer:
A white sheet of paper, a sketch pen, a clean beaker, and a tiny amount of clean water are all needed. Make a symbol (say “X”) on a white sheet. Place the empty beaker over the symbol that has been marked. We can see it well now. Fill the beaker with water now. Keep an eye out for the same mark. The mark has reappeared. Water is transparent, as evidenced by this observation.
Question 12.
Why is a tumbler not made with a piece of cloth?
Answer:
This is because we usually keep a liquid in a tumbler. Water cannot be kept in a tumbler made of a piece of cloth. As a result, a tumbler is built of a material that has the ability to hold liquid.
Question 13.
Explain with example rough and smooth surfaces.
Answer:
Rough surface: Materials with an uneven surface or ridges, such as coal, are considered rough surfaces.
A smooth surface is defined as a material that is plain and has an even surface, such as marble.
Question 14.
Name two gases each which are soluble and insoluble in water. «
Answer:
Oxygen and carbon dioxide are two gases that are soluble in water. Hydrogen and nitrogen are two gases that are insoluble in water.
Question 15.
Write any four properties of materials.
Answer:
Materials have four properties:
- Appearance
- Hardness
- Solubility or insolubility
- Float or buoyancy
- Transparency.
Question 16.
What are the similarities between iron, copper, aluminium?
Answer:
- They’re all lustrous.
- They’re all metal.
- They are hard.
Objective Type Questions
Question 1.
Match the following items given in Column A with that in Column B:
| Column A | Column B |
| (a) Glass, air | (i) Floats on water |
| (b) Iron sheet and cardboard | (ii) Translucent |
| (c) Oily paper sheet | (iii) Metallic lustre |
| (d) Sugar and salt | (iv) Transparent |
| (e) Gold and silver | (v) Opaque |
| (f) Wax | (vi) Soluble in water |
Answer:
| Column A | Column B |
| (a) Glass, air | (iv) Transparent |
| (b) Iron sheet and cardboard | (v) Opaque |
| (c) Oily paper sheet | (ii) Translucent |
| (d) Sugar and salt | (vi) Soluble in water |
| (e) Gold and silver | (iii) Metallic lustre |
| (f) Wax | (i) Floats on water |
Question 2.
Fill in the blanks with appropriate words:
- Grouping of things is done for ………….. .
- Classification is done on the basis of some ……………. and ………… .
- A thing can be made of different ……………. .
- Different materials can be used to make ……………. .
- Mustard oil is ……………….. in water.
- A sugar syrup is a ……………….. .
- Blue Vitriol (Neela though) is ……………… in water.
- Sand is ……………. in water.
- Lemon juice is ………………… in water.
- …………………. substances are those through which we can easily see.
- Materials which conduct heat quickly are called …………………….. of heat.
- Iron is a …………… material.
Answer:
- convenience
- Similarities, differences
- materials
- same thing
- immiscible
- solution
- soluble
- insoluble
- miscible
- Transparent
- conductor
- natural
Question 3.
State whether the statements given below are True or False:
- Grouping is a useful process.
- All objects are made up of same kind of materials.
- Things can be grouped on the basis of their shape and size.
- Different types of materials have different properties.
- Same thing can be made from different materials.
- Things made of gold and aluminium have no lustre.
- Use of a material depends on its properties and the purpose for which it is to be used. ,
- A looking mirror or thing made of metals are smooth to touch.
- All materials can be felt by one or more of our senses.
- The amount of matter in any object is called its weight.
- The materials which do not allow light to pass through them are called opaque,
- The materials which conduct heat very slowly are called non-conductor of heat.
Answer:
- True
- False
- True
- True
- True
- False
- True
- True
- True
- False
- True
- False
Question 4.
Choose the correct option in the following questions:
(i) What makes the basis of sorting materials into groups?
(a) Similarities in their properties
(b) Differences in their properties
(c) Both similarities and differences in their properties
(d) All of these
Answer:
(c) Materials are grouped on the basis of similarities and dissimilarities.
(ii) Which one will show a metallic lustre?
(a) Any surface of a metal
(b) Freshly cut surface of a metal
(c) Freshly cut surface of non-metal
(d) Surfaces of all materials
Answer:
(b) Metals when cut, their freshly cut surface shine.
(iii) An oily thin paper sheet will be
(a) transparent
(b) translucent
(c) opaque
(d) cannot be predicted
Answer:
(b) Only a part of the light passes through it.
(iv) Purpose of sorting material into groups is
(a) to study their properties
(b) convenience
(c) both (a) and (b)
(d) inconvenience
Answer:
(c) Materials are grouped for our convenience and to study their properties.
(v) Which is a set of transparent materials?
(a) Glass and air
(b) Water and glass
(c) Water and air
(d ) All of these
Answer:
(cl) Glass, air and water, all are transparent.
(vi) Choose the opaque object from the following:
(a) Charcoal
(b) Air
(c) Glass
(d) Water
Answer:
(a) Except charcoal, all three will allow the light to pass.
(vii) Which one of the following is not soluble in water?
(a) Turmeric powder
(b) Common salt
(c) Alum
(d) All are soluble
Answer:
(a) Only turmeric powder is not soluble in water.
(viii) Which object shines?
(a) Plastic toy
(b) Cotton shirt
(c) Steel spoon
(d) Stone piece
Answer:
(c) Steel spoon is a metallic object while all others are non-metals.
(ix) Which of the following has reddish-brown colour?
(a) Gold
(b) Copper
(c) Iron
(d) Brass
Answer:
(c) Iron has a reddish-brown colour.
(x) Which one of the following is insoluble in water?
(a) Alcohol
(6) Sodium chloride
(c) Coconut oil
(d) Sugar
Answer:
(c) Coconut oil is insoluble in water.
