CBSE Important Questions Class 6 Science Chapter 6 – Materials Around Us

Class 6 Science Chapter 6 Materials Around Us is part of the new NCERT textbook Curiosity. It teaches students that everything around us is made of some material, and that materials can be grouped by their properties. Students learn about matter, mass and volume, and about properties such as hardness and softness, shine, transparency (transparent, translucent and opaque), and solubility in water. They also learn why a particular material is chosen for a particular use.

These CBSE important questions for Class 6 Science Chapter 6 cover what counts as matter, transparent, translucent and opaque sheets, grouping materials, true and false statements about everyday objects, a table of transparency and solubility, choosing materials for a playground slide, a frying pan and a blanket, and natural versus man-made materials. Every question has a clear step-by-step answer in simple English, so students can practise on their own, parents can check the working, and teachers can use them for class tests. A free printable PDF of these important questions is also available on this page.

Q1. In a chemistry class, the teacher explains the concept of matter to the students. The teacher defines matter as anything that has mass and occupies space. The students are given various examples to determine which ones qualify as matter:
1. A rock
2. Air in a balloon
3. Light from a lamp
4. Water in a glass
5. Sound from a speaker
Based on the teacher's definition of matter, which of the following options correctly identifies the substances that are considered matter?
(a) 1, 2 and 4 only
(b) 1, 3 and 5 only
(c) 2, 4 and 5 only
(d) 1, 2, 3, 4 and 5

Answer: (a) 1, 2 and 4 only
A rock, the air in a balloon and water in a glass all have mass and take up space, so they are matter. Light and sound are forms of energy. They do not have mass and do not take up space, so they are not matter.

Q2. Three sheets of paper are tested for their transparency:
Sheet 1: Butter paper
Sheet 2: White tissue paper
Sheet 3: Paper painted with black acrylic paint
Which of the following is the correct statement regarding these sheets?
(a) All three sheets are transparent.
(b) Sheet 1 is translucent, Sheet 2 is transparent, and Sheet 3 is opaque.
(c) Sheet 1 and Sheet 2 are translucent, and Sheet 3 is opaque.
(d) Sheet 1 is opaque, Sheet 2 is translucent, and Sheet 3 is transparent.

Answer: (c) Sheet 1 and Sheet 2 are translucent, and Sheet 3 is opaque.
Butter paper and thin tissue paper let some light pass through, but we cannot see clearly through them, so they are translucent. Paper painted black does not let any light pass through, so it is opaque. None of them is transparent like clear glass.

Q3. Which of the following groups of materials are correctly grouped together?
(a) Iron, Sponge, Cotton
(b) Rubber, Cotton, Wool
(c) Stone, Wool, Plastic
(d) Diamond, Glass, Sponge

Answer: (b) Rubber, Cotton, Wool
Rubber, cotton and wool are all soft materials that we get from nature (rubber from the rubber tree, cotton from the cotton plant and wool from sheep). The other groups mix hard and soft materials, or natural and man-made materials, so they do not belong together.

Q4. Which of the following statements is/are correct?
Statement i: Tumblers are not made of cloth.
Statement ii: Handles of utensils are made of plastic or wood.
Statement iii: Sponge cannot be scratched easily with a metal key.
Statement iv: Oil is soluble in water.
(a) Statements i and ii are correct.
(b) Statements ii and iii are correct.
(c) Statements i, ii and iii are correct.
(d) All statements are correct.

Answer: (c) Statements i, ii and iii are correct.
Tumblers hold liquids, so they cannot be made of cloth (i is correct). Plastic and wood do not get hot quickly, so they are used for handles (ii is correct). A sponge is soft and springs back, so a key does not leave a scratch on it (iii is correct). Oil does not dissolve in water; it floats as a separate layer, so statement iv is wrong.

Q5. Which of the following properties is common among sugar, rock salt and oxygen gas?
(a) Transparency
(b) Shiny appearance
(c) Softness
(d) Solubility in water

Answer: (d) Solubility in water
Sugar and rock salt dissolve in water. Oxygen gas also dissolves in water, which is how fish and other water animals breathe. So all three are soluble in water. They do not share transparency, shine or softness.

Q6. Mass and volume are the two properties that are possessed by all materials. Anything that occupies space and has mass is called matter. The mass gives the quantity of matter, and the units to measure it are gram (g) and kilogram (kg). The space occupied by matter is its volume. The units to measure volume are litre (L) and millilitre (mL).
Answer the following questions based on the paragraph given above:
a. How do the concepts of mass and volume help in understanding the physical properties of matter?
b. Discuss the significance of using standardised units like grams, kilograms, litres and millilitres in scientific research.
c. How would you differentiate between mass and volume when describing a substance?

Answer: a. Mass tells us how much matter is in an object and volume tells us how much space it takes up. Together they help us compare materials, for example a small stone may have more mass than a large piece of sponge of the same volume.
b. Standard units mean that everyone measures in the same way. A scientist in one country can understand and check the results of a scientist in another country. This keeps measurements consistent, accurate and easy to compare.
c. Mass is the quantity of matter in a substance and is measured in grams or kilograms. Volume is the space the substance occupies and is measured in litres or millilitres. Two objects can have the same volume but different masses.

Q7. Once Priya's grandfather was telling her about his childhood days when he used to play with marbles. Priya asked, "How could you see the colours inside the marbles?" Grandfather replied, "The marbles were made of a special material".
a. What do you think the special material could be?
b. Why do you think this material was used for making marbles?
c. How does this material help in seeing the colours inside the marbles?

Answer: a. The special material is glass.
b. Glass is used for marbles because it is hard, it can be melted and shaped into smooth round balls, and it can be polished so that the marbles roll easily and last long.
c. Glass is transparent, so light passes through it. The coloured patterns are placed inside the glass while it is being made, and because the outer glass is transparent we can see these colours clearly.

Q8. Complete the table given below:

Answer: The completed table:

Honey lets only some light through and dissolves in water. Stone does not let light through and does not dissolve. Rock salt looks opaque but dissolves in water. Oxygen is an invisible, transparent gas that dissolves in water, which is how water animals get oxygen. Groundnut oil is translucent and does not mix with water.

Q9. Your class is tasked with designing a new playground slide. Considering only the materials shown in the image below are available, which 3 materials would be the most appropriate for ensuring safety and durability? Provide reasons for your selection.

Answer: The three best materials are metal, wood and plastic.
Metal: Metal is strong and hard, so it is best for the frame of the slide. It can bear the weight of many children and stays strong in sun and rain.
Wood: Wood is sturdy and can be used for the support and steps. Treated wood lasts long outdoors.
Plastic: Plastic is smooth, so it is best for the sliding surface. It is light, can be moulded into any shape and does not rust.
Wool, paper and cardboard are soft and get spoiled in rain, so they are not suitable.

Q10. Why is a frying pan not made of plastic?

Answer: Plastic cannot bear high heat. When heated strongly it softens, melts and may give off harmful fumes. A frying pan is made of metal because metal does not melt at cooking temperatures, and it spreads heat evenly so that food cooks well.

Q11. Imagine you are tasked with building a small outdoor shelter. Which materials would you choose, natural or man-made, and why?

Answer: A mix of both would be best.
Natural materials: wood for the frame, stone for the base and bamboo for parts that need to bend. These are strong, keep the inside cool and look natural.
Man-made materials: a plastic sheet or tarpaulin to keep rain out, and metal nails and screws to hold the parts firmly together.
Using both makes the shelter strong, weatherproof and long-lasting.

Q12. You are part of a team tasked with designing a new type of blanket. Your team is considering various materials, including wool, cotton and paper. During the discussion, one team member suggests using cotton to make the blanket. Do you think cotton is suitable for making a blanket? Explain with reason.

Answer: Yes, cotton is suitable for making a blanket.
• Comfort: Cotton is soft and feels pleasant on the skin.
• Breathability: Air can pass through cotton, so the body does not get too hot.
• Absorbency: Cotton soaks up sweat and keeps the user comfortable.
• Durability: Cotton is strong and can be washed many times.
Cotton is not as warm as wool, so for very cold places a wool blanket or a cotton-wool mix would be better. Paper is not suitable at all, because it tears easily and gives no warmth.

Related Study Material on Extramarks

• CBSE Important Questions Class 6 Science Chapter 1
• CBSE Important Questions Class 6 Science Chapter 2
• CBSE Important Questions Class 6 Science Chapter 3
• CBSE Important Questions Class 6 Science Chapter 4
• CBSE Important Questions Class 6 Science Chapter 5
• CBSE Important Questions Class 6 Science Chapter 7
• CBSE Important Questions Class 6 Science Chapter 8
• CBSE Important Questions Class 6 Science Chapter 9
• CBSE Important Questions Class 6 Science Chapter 10
• CBSE Important Questions Class 6 Science Chapter 11
• CBSE Important Questions Class 6 Science Chapter 12