Storing Materials into Groups

There is a vast variety of objects everywhere.

All objects around us are made up of one or more material.

Materials : The matter of which an object is made is called material. For example, glass, steel, wood etc.

A thing can be made from the same material.

Many things can be made from the same material.

Classification : The process of storing and grouping things according to some basis is called classification.

Basis of grouping :We can group materials on the basis of the similarities and differences in their properties.

Each material has its own properties, that may differ from others. However, some properties may be common to one or more materials.

Uses of a material : Uses of a material depends on its properties and the purpose for which it is to be used.

Metallic luster :Some materials have special shine on them which is called luster. Metals have luster while non-metals generally have no luster.

11.Smooth and rough surface : Some materials feel smooth on touching e.g., mirror and things made of metals and some other materials feel rough on touching for example, a piece of stone.

Hardness and softness : Materials which can be pressed easily are called soft while some other materials which cannot be pressed are called hard, for example, cotton is soft while wood is hard.


(i)            Substances that are dissolved in water are called soluble substances.
(ii)          Insoluble : Substances which do not dissolve in water are called insoluble.
(iii)         Miscible : Those liquids which mix well with water are said to be miscible in water.
(iv)         Immiscible :Substances which do not mix well with water are called immiscible in water.
(v)          Solubility of gases :Solubility of gases in water is very less.
(vi)         Oxygen gas which is dissolved in water, is very important for the survival of aquatic plants and animals.

14.Buoyancy : Some materials float in water while others sink :
(i)            Materials like sand, sugar and salt sink in water.
(ii)          Materials like wax, oil and wood float on water.

(i)            Opaque : Materials through which we are not able to seen are called opaque. For examples : wood, iron, gold.
(ii)          Translucent : Materials through which things are only partially visible are called translucent. For examples : Butter paper, old glass door.
(iii)         Transparent :Materials through which things can be seen are called transparent. For examples : Glass, water, air, test-tube.


16.Things are grouped together for convenience and to study their properties.
Q.1. Name five objects which can be made from wood.

Ans. Table, chair, bullockcart, boat, bed.

Q.2. Select those objects from the following which shine :

         Glass bowl, plastic toy, steel spoon, cotton shirt.

Among these glass bowl and steel spoon are shining objects.

Q.3. Match the objects given below with the materials from which they could be made. Remember, an object could be made from more than one material and a given material could be used for making many objects.


Q.4. State whether the statements given below are True or False :

Stone is transparent, while glass is opaque.
(ii)        A notebook has luster while eraser does not.
(iii)       Chalk dissolves in water.
(iv)       A piece of wood floats on water.
(v)        Sugar does not dissolve in water.
(vi)       Oil mixes with water.
(vii)     Sand settles down in water.
(viii)    Vinegar settles down in water.

Ans.   (i)False                (ii)False                (iii)False                  (iv)True
           (v)False               (vi)False               (vii)True                   (viii)True

Q.5. Given below are the names of some objects and materials :

         Water, basket ball, orange, sugar, globe, apple and earthen pitcher
Group them as :

Round shaped and other shapes
(b)  Eatable and non eatables

Ans. (a)
(i)Round shaped : basket ball, orange, globe, earthen pitcher.
        (ii)Other shapes : water, sugar, apple.

(i)Eatables : water, orange, sugar, apple.
     (ii)Non eatables : basket ball, globe, earthen pitcher.

Q.6. List all items known to you that float on water. Check and see if they will float on an oil or kerosene.

Ans. List of items that float on water :

         Wood, plastic, thermocol, oil etc.
         To students : Check and see yourself that above listed items will float on oil or

Q.7. Find the odd one out from the following :

Chair, Bed, Table, Baby, Cupboard
(b)  Rose, Jasmine, Boat, Marigold, Lotus
(c)  Aluminium, Iron, Copper, Silver, Sand
(d)  Sugar, Salt, Sand, Copper Sulphate


(a)  Baby (it is living while others are non-living).
(b)  Boat (except it all others are flowers).
(c)  Sand (except it all others are metals).
(d)  Sand (except it all others are soluble in water).


Q.1. Name any four materials that can be used to make school bags.

Cloth (of cotton, jute, nylon etc.) plastic, metal or alloy.

Q.2. List any three solution that are used in your home.

Salt solution, sugar solution, cold drinks, lime juice etc.

Q.3. List five each opaque and transparent materials.

Ans. Opaque materials :
(i)Wood, (ii)Iron, (iii)Cardboard,  (iv)Brick, (v)Gold.
Transparent materials : (i)Water, (ii)Glass, (iii)Air, (iv)Cellophine plastic, (v)Fibre glass.

Q.4. List five objects that are made from transparent materials.

(i) Beaker, (ii) Test tube, (iii) Conical flask, (iv) Crockery, (v) Glass doors, (vi) Glass jug.

Q.5. List five liquids that are transparent.

Water, Hydrochloric acid, Alcohol, Acetone, Petrol, Spirit etc.

Q.6. List five objects that are made from an opaque material.

Books, Black board, Cardboard, Wall Wooden furniture, etc.

Q.7. Why water is called universal solvents ?

The property of water to dissolve large number of materials makes it universal solvent.

Q.8. List three liquids which are miscible in water.

Milk, glycerine and soft drinks.

Q.9. List three
liquids which are immiscible in water.

Edible oils, kerosene oil and petrol.

Q.10. State conditions when pure water can loose transparency.

Water on cooling, freezes to form ice which is not transparent.

Q.11. List the following substances as soluble and insoluble in water.

          Sand, salt, sugar, paint, chilli powder, desi ghee, blotting paper.


Water soluble substances :
Salt, sugar, chilli powder.

Water insoluble substances :
Sand, paint, desi ghee, blotting paper.

Q.12. Why is mercury used in making thermometers ?


(i)    Mercury is liquid at room temperature.
(ii)  It is a good conductor of heat.
(iii)Mercury has luster, so, it is easy to read the temperature.

Q.13. Show that sugar, common salt and washing soda are soluble while chalk powder, iodine and sand are insoluble in water.

Take six test tubes, fill each of them about half with water. Keep each of them in a test tube stand. Add a pinch of each of six substances in separate test tubes. Shake well and allow to stand for few minutes. Common salt, sugar and washing soda dissolves while iodine, chalk powder and sand do not dissolve.

Q.14. Describe a method to prove that water is a transparent material.

Take a white sheet of paper, one sketch pen, one clean beaker and a small quantity of clean water. Now on white sheet mark a symbol (say ‘X’). Now put the empty beaker over the marked symbol. We can see it properly. Now put water in the beaker. Observe the same mark. The mark is again visible. This observation proves that water is transparent.

Q.15. Why is a tumbler not made with a piece of cloth ?

This is because we generally use a tumbler to keep a liquid. A tumbler made of a piece of cloth can not be used to keep water. So, a tumbler is made with a material which has a property to hold the liquid.

Q.16. On what basis are the various objects grouped ?

The grouping of various objects can be done on the basis of following characters :

(i)size, (ii)shape, (iii)colour, (iv)hardness, (v)solubility in water, (vi)attraction towards magnet, (vii)conduction of heat, (viii)transparency etc.

Q.17. Why do we need the grouping of objects ?

Grouping the things help us to arrange them in systematic manner. The things when grouped are easy to handle. When grouped, it is easy to know the properties of object clearly. It also makes easy to compare two objects.

Q.18. How does the grouping of objects helps the shopkeeper ?

The grouping of objects in proper way make it easier to work. When we go to purchase something, the shopkeeper locates it easily, because there are separate shelves to put various items and similar things are kept at one place. If he randomly places all of these, he would never be able to find it so quickly and easily.

Q.19. Name the various materials from which following things can be made.

          Shoes, chair, coins, utensils, clothes.


(i)    Shoes : Leather, rubber, plastic, canvas
(ii)  Chair : Wood, metal, plastic, concrete
(iii)Coins : Copper, silver, gold
(iv)Utensils : Iron, copper, aluminium
(v)  Clothes : Cotton, wool, silk, rayon, nylon.


Q.1. Match the following items given in Column A with that in Column B.

Column AColumn B
(a)  Glass, air
(b)  Iron sheet and card board
(c)  Oily paper sheet
(d)  Sugar and salt
(e)  Gold and silver
(f)   Wax
(i)            Floats on water
(ii)          Translucent
(iii)         Metallic luster
(iv)         Transparent
(v)          Opaque
(vi)         Soluble in water
Q.2. Fill in the blanks with appropriate words :

Grouping of things is done for ……… .
(ii)          Classification is done on the basis of some ……….. and ………… .
(iii)         A thing can be made of different ………. .
(iv)         Different materials can be used to make ……….. .
(v)          Mustard oil is ……….. in water.
(vi)         A sugar syrup is a ……… .
(vii)       Blue Vitroil (Neela thotha) is ………. in water.
(viii)      Sand is ………… in water.
(ix)         Lemon juice is ………. in water.
(x)          ………… substances are those through which we can easily see.
(xi)         Materials which conduct heat quickly are called ……….. of heat.
(xii)       Iron is a …………. Material.

Q.3. State whether the statements given below are True or False :

Grouping is a useful process.
(ii)          All objects are made up of same kind of materials.
(iii)         Things can be grouped on the basis of their shape and size.
(iv)         Different types of materials have different properties.
(v)          Same thing can be made from different materials.
(vi)         Things made of gold and aluminium have no luster.
(vii)       Use of a material depends on its properties and the purpose for which it is to be used.
(viii)      A looking mirror or things made of metals are smooth to touch.
(ix)         All materials can be felt by one or more of our senses.
(x)          The amount of matter in any object is called its weight.
(xi)         The material which do not allow light to pass through them are called opaque.
(xii)       The material which conduct heat very slowly are called non-conductor of heat.

Q.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)  None of these

Which one will show a metallic luster ?
(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

An oily thin paper sheet will be
(a)transparent                                    (b)translucent
(c)opaque                                           (d)cannot be predicted

Purpose of sorting material into groups is
(a)to study their properties                  (b)convenience
(c)both (a) and (b)                               (d)none of these

Which is a set of transparent materials ?
(a)Glass and air                                   (b)Water and glass
(c)Water and air                                   (d)All of these

Choose the opaque object from the following :
(a)Charcoal                                          (b)Air
(c)Glass                                               (d)Water

Which one of the following is not soluble in water ?
                 (a)Turmeric powder                             (b)Common salt
                 (c)Alum                                                (d)All are soluble

Which object shines ?
                 (a)Plastic toy                                         (b)Cotton shirt
                 (c)Steel spoon                                       (d)Stone piece

Which of the following has reddish brown colour ?
(a)Gold                                                   (b)Copper
(c)Iron                                                     (d)Brass

Which one of the following is insoluble in water ?
(a)Alcohol                                              (b)Sodium chloride
(c)Coconut oil                                        (d)Sugar


Q.1. Match the items in Column A with Column B :

Column AColumn B
(a)  Glass, air
(b)  Iron sheet and card board
(c)  Oily paper sheet
(d)  Sugar and salt
(e)  Gold and silver
(f)   Wax
(v)  Opaque
      (vi)Soluble in water
      (iii)Metallic luster
(i)   Floats on water
Q.2. Fill in the blanks :
        (i)convenience                     (ii)similarities, differences            (iii)materials
        (iv)same thing                      (v)immiscible                               (vi)solution
        (vii)soluble                           (viii)insoluble                                (ix)miscible
        (x)Transparent                     (xi)conductor                                (xii)natural
Q.3. True/False :
         (i)True                   (ii)False                           (iii)True                     (iv)True
         (v)True                  (vi)False                          (vii)True                    (viii)True
         (ix)True                 (x)False                           (xi)True                     (xii)False
Q.4. Choose the correct option :
(i)              (c) Materials are grouped on the basis of similarities and dissimilarities.
(ii)            (b) Metals when cut, their freshly cut surface has shining.
(iii)           (b) Only a part of light passes through it.
(iv)           (c) Material are grouped for our convenience and to study their properties.
(v)            (d) Glass, air and water, all are transparent.
(vi)           (a) Except charcoal all the three will pass the light.
(vii)          (a) Only turmeric powder is not soluble in water.
(viii)        (c) Steel spoon is a metallic object while all others are non-metals.
(ix)           (c) Iron has reddish brown colour.
(x)            (c) Coconut oil is insoluble in water.