These NCERT Solutions for Class 6 Science Chapter 4 Sorting Materials into Groups Questions and Answers are prepared by our highly skilled subject experts to help students while preparing for their exams.
Sorting Materials into Groups NCERT Solutions for Class 6 Science Chapter 4
Class 6 Science Chapter 4 Sorting Materials into Groups Textbook Exercise Questions and Answers
Name five objects which can be made from wood.
Table, chair, doors, boat and bed.
Select those objects from the following which shine:
Glass bowl, plastic toy, steel spoon, cotton shirt
Glass bowl and steel spoon are shining objects.
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.
|Tumbler||Glass and Plastic|
|Chair||Wood and Plastic|
|Toy||Plastic and Wood|
State whether the statements given below are True or False:
a. Stone is transparent, while glass is opaque.
b. A notebook has lustre while eraser does not.
c. Chalk dissolves in water.
d. A piece of wood floats on water.
e. Sugar does not dissolve in water.
f. Oil mixes with water.
g. Sand settles down in water.
h. Vinegar dissolves in water.
Given below are the names of some objects and materials:
Water, basketball, orange, sugar, globe, apple and earthen pitcher
Group them as:
a. Round shaped and other shapes
b. Eatables and non-eatables
a. (i) Round shaped: Basketball, apple, orange, globe, earthen pitcher
(ii) Other shapes: Water, sugar
b. (i) Eatables: Water, orange, sugar and apple
(ii) Non-eatables: Basketball, globe and earthen pitcher
List all items known to you that float on water. Check and see if they will float on an oil or kerosene.
- Dried leaves
All these materials float on water and they sink in oil or kerosene.
Find the odd one out from the following:
a. Chair, Bed, Table, Baby, Cupboard
b. Rose, Jasmine, Boat, Marigold, Lotus
c. Aluminium, Iron, Copper, Silver, Sand
d. Sugar, Salt, Sand, Milk, Milk powder
NCERT Extended Learning Activities and Projects
You may have played a memory game with your friends. Several objects are placed on a table, you are asked to observe them for a few minutes, go into another room and write down the names of all objects that you can remember. Play this game, with a difference! Ask all the participants in the game to remember objects with some particular property’ while playing this memory game – remember and write down the names of objects that were made of wood or objects that are edible and so on. Have fun!
Do it yourself.
From a large collection of materials, make groups of objects having different properties like transparency, solubility in water and other properties. In later chapters you will also learn about properties of materials related to electricity and magnetism. After making different groups from the collected materials, try and find out if there are any patterns in these groups. For instance, do all materials which have lustre conduct electricity?
Hint: It is not necessary to find a correlation between all properties. For example, mirror has lustre but does not conduct electricity.
Objective: To study whether the given material is soluble or insoluble in water.
Materials Required: Water, sugar, chalk, washing soda, sand, copper sulphate and sulphur.
- Take 6 beakers and fill each of them to half with water.
- Add a pinch of sugar, chalk powder, washing soda, sand, copper sulphate and sulphur in separate beakers.
- Stir the contents of each beaker well and allow them to stand for a while.
- Observe after few minutes.
Observations: Particles of sugar, washing soda and copper sulphate have disappeared. Chalk powder, sand particles and sulphur are left as such.
Conclusion: Sugar, washing soda and copper sulphate are soluble in water. Sand, chalk powder and sulphur are insoluble in water.
Objective: To study the solubility of different liquids in water.
Materials Required: One spoon each of vinegar, lemon juice, honey, milk, coconut oil, mustard oil, kerosene and seven glass tumblers with water.
- Add a small amount of vinegar to the first glass, lemon-juice to the second and similarly, add small amounts of the other liquids into other glasses containing water.
- Stir contents of each of them with a spoon. Wait for 5 minutes.
Observations: Vinegar, lemon juice, honey and milk have completely dissolved in water. Such liquids are miscible liquids. Liquids like coconut oil, mustard oil and kerosene have not dissolved. Such liquids are immiscible or insoluble liquids.
- Metal: It is a hard, shiny, usually solid material which is able to be shaped and can conduct or allow electricity and heat to pass through it.
- Transparency: Light can pass through certain objects. Due to this, we are able to see through the objects. This property of materials to allow light to pass through them and enable visibility is called transparency. On this basis, objects can be of three types:
i. Transparent: If almost all the light can pass through an object, it is called transparent. We can see clearly through transparent materials such as air, water and a clear glass.
ii. Opaque: If no light can pass through an object, it is called opaque. We cannot see through an opaque material at all, such as cardboard, milk, stone and metal.
iii. Translucent: If light can pass through an object partially, it is called translucent. We cannot clearly see through a translucent material such as a frosted glass, turbid water and dust-laden air. Such materials allow partial visibility.
Objective: To distinguish between transparent, opaque and translucent materials.
Materials Required: Apiece of a clear glass, a cardboard, oily paper and torch.
- Take a torch and point it to each of the three objects-a clear glass, a cardboard and oily paper one by one.
- Write down what happens when light is pointed to each of the objects.
Observation: Light passes through the piece of glass. No light passes through the cardboard. Only a little amount of light passes through the oily paper.
Conclusion: Glass is a transparent material as it allows the light to pass through it. Cardboard is an opaque material as it does not allow the light to pass through it. The oily paper is a translucent material as it allows only some light to pass through it.
- Rough or Smooth: An object having an uneven or irregular surface is said to be rough, such as sandpaper. On the other hand, object having a smooth and levelled or a polished surface is said to be smooth. For example, mirror and metals.
- Floatation: Many materials float, whereas many others sink in water. This property is called floatation. Materials such as wool, leaves and feathers float on the water whereas rocks and metals sink.
- Density: The mass per unit volume of a substance is known as its density. Materials which are less dense than water float on it. Materials denser than water sink in it.
Objective: To classify different materials on the basis of floatation.
Materials Required: Wooden piece, dry leaf, pebble, eraser, iron nail, pencil, table tennis ball and a bucket half-filled with water.
- Take all these materials at a time and drop them in the bucket of water.
- Observe whether each material float on water or sink to the bottom of the bucket.
Observations: Some materials like dry leaf, pencil, wooden piece and table tennis ball float on the surface of water. Materials like eraser, pebble and iron nail sink to the bottom of the bucket.
Conclusion: Some materials float on water while others sink.
Materials can also be grouped on the basis of whether the object is solid, liquid or gas, whether it is conductor of heat or it is a non-conductor of heat. For example, metals are conductors of heat but wood and plastics are non-conductors of heat.
Need to Group Materials: We group materials due to the following uses:
- Sorting of materials into groups makes it convenient for us to view them.
- We can store similar things together and hence can locate them easily.
- Dividing materials into groups makes it convenient to study their properties and the patterns in these properties.
Class 6 Science Chapter 4 Sorting Materials into Groups Additional Important Questions and Answers
Very Short Answer Type Questions
Why do we need to group materials? Give reason.
We often group materials for our convenience. It helps to describe their properties.
Is a substance which can be compressed soft or hard?
Choose a lustrous material out of the following substances:
Wood, aluminium, plastic, cotton
Name two objects made from opaque materials.
Wooden doors and blackboard.
What is a translucent object?
Materials that allow light to pass through them partially are called translucent.
Name three things made from glass.
Bowls, mirrors and windowpanes.
Name any three materials that can be used to make school bags.
Cotton, jute and leather.
Name two gases which are insoluble in water.
Hydrogen and nitrogen.
Name any three objects having rough surface.
The bark of tree, rock and sand paper are objects having rough surface.
Density is mass per unit volume of a substance.
Short Answer Type Questions
Why is a tumbler not made with a piece of cloth?
We use tumblers made of glass, plastic and metal to keep a liquid. These substances can hold a liquid. A tumbler made of cloth cannot hold a liquid because:
- cloth piece is not hard enough to hold liquids, and
- cloth piece has very minute pores through which the liquid oozes out.
Make a table and state whether the following materials mix with water or not.
Vinegar, lemon juice, mustard oil, coconut oil and kerosene.
|Liquids||Mixes well/Does not mix|
|1. Vinegar||Mixes well|
|2. Lemon juice||Mixes well|
|3. Mustard oil||Does not mix|
|4. Coconut oil||Does not mix|
|5. Kerosene||Does not mix|
Name five objects each which can be made from the following materials:
wood, cotton, leather, paper
|1. Wood||Table, chair, doors, windows, book-rack|
|2. Cotton||Fabric (clothes), pillows, mattresses, quilts, wicks|
|3. Leather||Shoes, bags, purses, suitcase, sofa|
|4. Paper||Books, notebooks, newspaper, calendars, envelopes|
Metals generally occur in solid state and are hard in form. Name a metal that exists in liquid state and a metal that is soft and can be cut with knife.
Mercury is a metal that exists in liquid state. Sodium and Potassium are soft metals and can be cut with knife.
Why do we cook food in utensils made of aluminium or other metallic materials?
Cooking utensils which are used to cook food are made from aluminium or other metals. The reason is that metals are good conductors of heat. They allow the transmission of heat through them and food cooks quickly. Therefore, utensils are made of metals.
Universal solvent (water) is very essential for the human body. Why?
The universal solvent is able to dissolve a number of substances. So it is essential for the human body. It constitutes a major part of the cells located in human body. All materials are transported across the body in dissolved form.
Classify the following into transparent, translucent and opaque materials.
Butter paper, cardboard, ground glass, clear glass, water, air, brick, wall, aluminium sheet
Transparent: Clear glass, water, air
Translucent: Butter paper, ground glass
Opaque: Cardboard, brick, wall, aluminium sheet
Classify the following into hard materials and soft materials.
Cotton, iron, diamond, chalk, wood, wax, clay, sponge, bone, feathers
Hard materials: Iron, diamond, wood, bone, chalk
Soft materials: Cotton, wax, clay, sponge, feathers
Write three common characteristics of materials.
- All materials can be felt by one or more of our senses.
- All materials occupy space.
- All materials possess mass.
Write a short note on texture.
Materials may be rough or smooth. The surface of paper or a glass tumbler feels smooth since there are no uneven surfaces. The bark of tree, rock and sandpaper are rough to touch because their surfaces are uneven and bumpy. So, materials can be classified on the basis of their texture.
Write a short note on floatation.
Many materials float, whereas many others sink in water. This property is called floatation. Materials such as wood, leaves and feathers float on the water whereas rocks and metals sink. If you weigh equal volumes of cotton and water, the cotton weigh less than water as cotton is less dense than water.
Long Answer Type Questions
What is classification? How is it useful? Explain with examples.
The method of grouping objects on the basis of certain similarities and dissimilarities is called classification. We can understand the importance of classification with the help of simple examples.
a. The things in your house are the most common examples. You classify or group them while arranging them. You keep the utensils in the kitchen, the books in the study room and the bed in the bedroom. It helps in locating the things easily.
b. Classification also enables us to make a systematic study of anything. For example, if you observe the way things have been stocked in your kitchen, you will find that various items are classified. Certain items are classified as spices and stocked together.
Other items may be required for a common activity, say, making a tea. Hence, these are stocked together. You also classify your items and arrange your study table in such a way that you do not have to waste time trying to locate a given item.
Define solubility of materials in water. Give examples.
Some materials are soluble in water whereas some are insoluble. For example, sugar is soluble in water whereas sand is insoluble. Actually, water causes all molecules in a solid piece of sugar to break apart. The individual molecules, when separated, are so small that we cannot see them. We can say that sugar is soluble in water. Some solids like sugar and common salt are soluble in water.
On the other hand, sand is insoluble in water. It settles down in water and does not dissolve even on stirring. Some solids are insoluble in water, e.g., wood, stone, chalk and wax. Materials in each state can therefore be classified on the basis of their solubility in water.
Define the properties of matter.
Some important properties of matter are discussed below:
- Appearance: Materials can be classified on the basis of their appearance. Different materials have different appearance.
- Lustre: Materials can be classified on the basis of their lustre or shine. Some shine a lot whereas others are quite dull.
- Texture: Different materials feel different when touched, so they have different textures. Some can be rough and others can be smooth.
- State: Most materials can be placed into one of the three states: solid, liquid or gas.
- Solubility in water: Some materials are soluble in water whereas some are insoluble. Miscible liquids mix with each other while immiscible liquids do not.
- Transparency: If almost all the light can pass through an object, it is called transparent. If no light can pass through an object, it is called opaque. If light can pass through an object partially, it is called translucent.
Observe the given picture and answer the questions.
a. Why should we not use a tumbler made of cloth?
b. What inference can we draw from it?
a. Tumbler made of cloth cannot hold water.
b. We should choose a material to make an object depending on its properties and the purpose for which the object is to be used.
a. Identify the objects A, B, C and D shown below.
b. Which of these can float on water?
c. Which of these will sink in water?
a. A-Leaf, B-Iron, C-Feather, D-Wood.
b. Leaf, feather and wood.