Class 6 Science Chapter 4 Important Question & Answer

Important Questions Class 6 Science Chapter 4 – Sorting Materials into Groups

Science is a body of knowledge that is subjected to the natural and physical world gained through observation and experimentation and organised systematically. . It is the method of reconciling practical ends with scientific laws. The aim of Science is to seek the simplest explanation of complex facts. Sorting Materials into Groups is the fourth chapter in the Class 6 Science syllabus. This lesson deals with the objects and the materials they are made of, properties of materials such as appearance, hardness, solubility, and transparency. Sorting materials into groups makes it easier to locate and work with them. In general,  science entails the search of knowledge pertaining to universal truths or how fundamental laws operate.

Each object is made of different materials, and different types of objects can be made from the same materials too. Hence we must know about the properties of materials. The first thing that we have to take into consideration is the appearance of the material. Some materials are lustrous in nature, and some are full in appearance. The next thing we have to consider is that hardness. Hardness can be determined by the compression given to that material. If the material is compressed or scratched easily, it is called a soft material; if the material is difficult to compress or scratch, it is called a hard material. It is also necessary to check the solubility of the materials, i.e. whether it is soluble or insoluble in water. The final thing we must consider is the  transparency of the material. Materials can be classified as transparent, opaque and translucent based on the transmittance of light by them.

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Extramarks provides comprehensive study materials such as NCERT solutions, CBSE revision notes, CBSE sample papers, CBSE past years’ question papers, and more. Important questions Class 6 Science Chapter 4 contains various questions from different sources such as NCERT books, NCERT exemplars, and other references. Solving important questions Class 6 Science Chapter 4 helps the students to revise the concepts and recall their syllabus.

Important Questions Class 6 Science Chapter 4 – With Solutions

Important questions Class 6 Science Chapter 4 comprise a wide variety of topics which includes the objects and the material they are made of and properties of materials such as appearance, hardness, solubility, and transparency. Solving these questions gives you a good idea about the level of questions expected  in the examination.

Mention below are a few questions and their solutions from our important questions Class 6 Science Chapter 4 :

Question 1. You are provided with the following materials

(i) magnifying glass

(ii) mirror

(iii) stainless steel plate

(iv) glass tumbler.

Which of the above materials will you identify as transparent?

(a) (i) and (ii)

(b) (i) and (iii)

(c) (i) and (iv)

(d) (iii) and (iv)

Answer 1: (c) (i) and (iv)

Explanation: Magnifying glass and glass tumbler are transparent.

Question 2. Boojho found a bag which includes the following materials.

(i)  Paper stained with oil

(ii) Glass spectacles

(iii) Magnet

(iv) Mirror

Help Boojho in finding out the material(s) which is/ are opaque.

(a) (i) only

(b) (iv) only

(c) (i) and (iii)

(d) (ii) and (iv)

Answer 2: (c) (iv)  and (iii)

Explanation: Since the mirror is painted on one side, it is opaque. Since the magnet is made up of iron metal, it is opaque.

Question 3. While doing an activity in class, the teacher asked Paheli to hand over translucent material. Which among the following materials will Paheli pick and give it to her teacher?

(a) Glass tumbler

(b) Mirror

(c) Muslin cloth

(d) Aluminium foil

Answer 3: (c) Muslin cloth

Explanation:  Glass tumbler is transparent, and the mirror and aluminium foil are opaque. Muslin cloth is translucent because it allows us to see through them, although dimly.

Question 4. lt was Paheli’s birthday. So her grandmother presented her two gifts made of metals, one old dull silver spoon and a pair of lustrous gold earrings. She was so surprised to see the difference in the appearance of the two metals. Can you explain the reason for this difference?

Answer 4: Due to the noble nature of gold, it does not react with the gases in the environment. In humid air, silver loses its lustre due to reactions with certain gases, such as hydrogen sulphide.

Question 5. Which among the following materials would you identify as soft materials and why? Ice, rubber band, leaf, eraser, pencil, pearl, a piece of the wooden board, cooked rice, pulses and fresh chapati.

Answer 5: Rubber band, eraser, leaf, cooked rice and fresh chapati are soft materials because they can be scratched or compressed easily.

Question 6. You are provided with the following materials:

( Turmeric, honey, mustard oil, water, glucose, rice flour, and groundnut oil. )

Make any three pairs of substances where one substance is soluble in the other and any three pairs of substances where one substance remains insoluble in the other substances.

Answer 6 :

1. Soluble pairs

(i) Honey – water

(ii) Mustard oil – groundnut oil 

(iii) Glucose – water

1. Insoluble pairs

(i) Turmeric – water

(ii) Rice flour – water

(iii) Mustard oil – water

Question 7. Categorise the jumbled words to arrive at the appropriate names of materials and write two uses of each.

(a) milaunuim

(b) tcaslpi

(c) soekrnee

(d) gavnier

Answer 7:

(a) Aluminium –  wrapping food items, kitchen utensils, making aircraft, etc.

(b) Plastic – To make the covering of electric wires and handles of tools, Pencil boxes, etc.

(c) Kerosene – Fuel, cooking, solvent, etc.

(d) Vinegar – Preservative, food ingredients, etc.

Question 8. List five objects which can be made from wood.

Answer 8: Five objects which can be made from wood are:

• Table
• Chair
• Doors 
• Bed
• Pencil

Question 9. Match the objects below with the materials from which they could be made. Remember, a given material could be used for making many objects, and an object could be made from more than one material,

Answer 9:

Question 10. State whether the following statements are ‘true’ or ‘false’.

(i) A notebook has lustre while an eraser does not.

(ii)  Glass is opaque transparent, while 

the stone is transparent. 

(iii)  A piece of wood floats on water.

(iv) Chalk dissolves in water.

(v) Oil mixes with water.

(vi)  Sugar does not dissolve in water.

(vii) Sand settles down in  water.

(viii) Vinegar dissolves in water.

Answer 10 : 

(i) False; A notebook and an eraser do not have the property of lustre, as they are non-metals.

(ii) False;  Stone is opaque, while glass is transparent.

(iii) True

(iv) False; Chalk is insoluble in water.

(v) False; Oil is immiscible in water. It forms a separate layer on the surface of the water.

(vi) False; Sugar is completely soluble in water.

(vii) True

(viii) True

Question 11. Mentioned 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

Answer 11: 

(a) (i) Round shaped: Basketball, orange, apple, globe, earthen pitcher.

(ii) Other shapes: Water, sugar.

(b) (i) Eatables: Water, sugar, orange, and apple.

(ii) Non-eatables: Basketball, globe and earthen pitcher.

Question 12. List three liquids which are transparent.

Answer 12: 

• Acetone
• Water
• Alcohol

Question 13. Write any four properties of materials.

Answer 13: 

• Appearance
• Hardness
• Solubility
• Float or sink in water
• Transparency

Question 14. Why isn’t a tumbler made with a piece of cloth?

Answer 14: To keep a liquid, we use tumblers made of glass, plastic, and metal. These materials can accommodate liquid.

The following are the reasons why a tumbler made of cloth is unable to contain liquid: 

(i) Cloth piece has incredibly small holes through which the liquid seeps out.

(ii) It is not hard enough to hold liquids. 

Question 15. Mention the similarities between iron, copper and aluminium.

Answer 15: 

(a) They are hard,

(b) They all have lustre, 

(c) They are all metals.

Question 16. Why is water called a universal solvent?

Answer 16: Numerous materials are dissolved in water. So it is known as a universal solvent.

Question 17. Demonstrate an experiment to show that our palm is translucent.

Answer 17: 

• In a dark area, cover a torch’s glass with your palm. 
• Turn on the torch and look at your palm from the opposite side.. 
• Though not clear, we can see that the torch light is transmitted through the palm. 
• This experiment demonstrates that when a powerful light beam travels through our palm, it becomes  translucent.

Question 18. How can you illustrate that some solids like sugar and salt are soluble in water, whereas solids like chalk powder and sand are not soluble in water?

Answer 18 : 

Gather samples of sand, salt, chalk powder, and sugar. Take four beakers. Each one should be roughly two-thirds full of water. Add one teaspoon of sugar to the first beaker. Then add salt to the second, chalk powder to the third and sand to the fourth. Use a spoon or stirrer to stir the contents of each beaker. Wait for a few minutes. Observe what happens to the substances that have been added to the water. Write down your observations in the table that follows.

Inference:

(i) Both chalk powder and sand are insoluble in water. 

(ii) Sugar and salt both dissolve in water.

Question 19. Chalk, iron nail, wood, aluminium, candle, and cotton usually look different. Give some properties by which we can prove that these materials are different.

Answer 19:

• Chalk – Hard, rough, non-lustrous
• Wood – Hard, rough, non-lustrous
• Aluminium – Hard, smooth, lustrous
• Candle – Hard, smooth, non-lustrous
• Cotton – Soft, smooth, non-lustrous
• Iron nail – Hard, smooth, lustrous

Question 20. Show that sugar, common salt and washing soda are soluble while chalk powder, iodine and sand are insoluble in water.

Answer 20:

• Take six test tubes.
• Add water to each one until it is about halfway full. 
• Each one should be kept in a test tube stand. 
• Add a tiny amount of each of the six substances in separate test tubes.
• Shake vigorously and let stand for a few minutes. 
• Iodine, chalk powder, and sand are insoluble, while table salt, sugar, and washing soda dissolve.

Question 21. Differentiate among opaque, translucent and transparent materials, giving one example.

Answer 21: 

Opaque material: Opaque substances are those substances through which objects cannot be seen. Example: wood, stone.

Translucent material: Translucent substances are those substances through which objects can be seen but not clearly. Example: oiled paper, frosted glass. 

Transparent material: Transparent substances are those substances through which objects can be seen clearly. Example: glass, clear water.

Question 22.

Mixtures of red chilli powder in water, butter in water, petrol in water, and honey in water were given to Radha, Sudha, Sofia and Raveena, respectively. Whose mixture is in solution form?

Answer 22: Since honey and water are miscible in one another, combining the two will result in a solution. Raveena will obtain the mixture in solution form.

Question 23. Which of the following assertions is not true?

(a) Materials are grouped for convenience.

(b) Materials are grouped to study their properties.

(c) Materials are grouped for fun.

(d) Materials are grouped according to their uses.

Answer 23 : 

(c): Materials are not grouped for fun. They are organised into groups for convenience, to study their characteristics, and in an organised manner in accordance with their applications.

Question 24. Why is mercury used in making thermometers?

Answer 24: Mercury is the only metal in a liquid state at room temperature. It is used in thermometers because it has a high coefficient of expansion. Because of this, even a small temperature change can be felt using a thermometer. It is also particularly good for measuring greater temperatures because of its high boiling point. Additionally, it looks sparkling and doesn’t adhere to glass surfaces.

Question 25. How does the grouping of objects help the shopkeeper?

Answer 25: It is easier to work when objects are grouped properly. There are separate shelves for different items, and comparable items are stored together so that when we buy anything, the shopkeeper can simply find it. He would never be able to locate them so fast and simply if he had just placed each of these items randomly..

Question 26. List five objects that are made from transparent materials.

Answer 26:

• Beaker
• Test tube
• Windows
• Conical flask
• Fish tank

Question 27. List three liquids which are immiscible in water.

Answer 27: Three liquids which are immiscible in water are:

• Kerosene oil
• Petrol
• Diesel

Question 28. Discuss the solubility of gases in water. What is the significance of oxygen gas dissolved in water? How is the carbon dioxide gas dissolved in water helpful to aquatic plants?

Answer 28: While certain gases are insoluble in water, others are soluble. Water can dissolve oxygen gas. The oxygen dissolved in water is used for respiration by plants and animals that dwell in the water. Therefore, oxygen that has been dissolved in water is crucial for the survival of aquatic creatures and plants.

Water can dissolve carbon dioxide gas as well. For the process of photosynthesis, aquatic plants require the carbon dioxide gas that has been dissolved in the water.

Benefits of Solving Important Questions Class 6 Science Chapter 4

Solving important questions Class 6 Science Chapter 4 would enhance students’ knowledge, and they would understand how questions are asked. Moreover, solving questions from our question bank will also help them categorise questions into varying levels of  difficulty.

Below are a few benefits of regularly solving questions from our Chapter 4 Class 6 Science important questions:

• The questions are given in a format that’s similar to a real examination paper. It will help students analyse their knowledge about the chapter and they would also get a sense about time management.
• In order to make this learning process more interesting and enjoyable within the limited timeframe, subject matter experts at Extramarks had to dig deeper to restructure the information into different formats to enable a smooth and deep learning experience so that students need not look elsewhere for any other reference material.
• Subject experts have created several pointwise notes that help students conveniently recall the crucial points in the exam and use these solutions for last-minute revisions
• By solving Class 6 Science Chapter 4 important questions, students will understand the scoring pattern and they can prepare their strategy and timetable accordingly.
• Solving Important Questions Class 6 Science Chapter 4 also enhances their problem-solving skills. It also helps them to analyse your performance, strengthen their weak zones and rectify your mistakes. This will definitely boost their confidence and help improve  their score in the exams..

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