Practice Questions: Sorting Materials into Groups | Practice Questions with Solutions for Class 6 PDF Download

Q1: List three liquids which are immiscible in water.
Ans: Three liquids which are immiscible in water are:

• Kerosene oil
• Petrol
• Diesel

 
Q2: 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?
Ans: 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.

Q3: Why is mercury used in making thermometers?
Ans: 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.

Q4: How does the grouping of objects help the shopkeeper?
Ans: 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.

Q5: List five objects that are made from transparent materials.
Ans:

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

Q6: 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?
Ans: 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.

Q7: 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.
Ans: (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.

Q8: Show that sugar, common salt and washing soda are soluble while chalk powder, iodine and sand are insoluble in water.
Ans:

• 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.

 
Q9: Differentiate among opaque, translucent and transparent materials, giving one example.
Ans:

• 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.

Q10: Chalk, iron nail, wood, aluminium, candle, and cotton usually look different. Give some properties by which we can prove that these materials are different.
Ans:

• 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

Q11: Why is water called a universal solvent?
Ans: Numerous materials are dissolved in water. So it is known as a universal solvent.

Q12: Demonstrate an experiment to show that our palm is translucent.
Ans: 

• 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.

Q13: Why isn’t a tumbler made with a piece of cloth?
Ans: 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: 

• Cloth piece has incredibly small holes through which the liquid seeps out.
• It is not hard enough to hold liquids. 

Q14: Mention the similarities between iron, copper and aluminium.
Ans: (a) They are hard,
(b) They all have lustre,
(c) They are all metals.

Q15: List three liquids which are transparent.
Ans:

• Acetone
• Water
• Alcohol

 
Q16: Write any four properties of materials.
Ans:

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

Q17: 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
Ans: (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.

Q18: 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
Ans: (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.

Q19: List five objects which can be made from wood.
Ans: Five objects which can be made from wood are:

• Table
• Chair
• Doors 
• Bed
• Pencil

Q20: 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.
Ans: Rubber band, eraser, leaf, cooked rice and fresh chapati are soft materials because they can be scratched or compressed easily.