Hint: List the objects around us in order to analyse the materials they are made up of.
Question.1. From the given list, which pair of objects could be made of both, plastic and metal components?
A: Toothbrush
B: Saree
C: Spectacles
D: Buckets
E: Frying pan
(a) A and E
(b) B and C
(c) D and E
(d) A and D
Question.2. An ordinary chair requires a strong structure to support the weight of a person sitting on it. Which of the following materials should not be considered for building a chair?
(a) Glass
(b) Metal
(c) Wood
(d) Plastic
Ans.1. (c) D and E
Ans.2. (a) Glass
Hint: Plan and conduct an investigation in order to classify different kinds of materials by their observable properties.
Question.3. A student collected spoons made of plastic, metal, ceramic and wood. She then noted down conditions under which each of these would be ineffective. Which of the following observations should be in her notes?
(a) Wooden spoon will let liquids pass through it
(b) Metallic spoon can easily bend on applying pressure
(c) Plastic spoon could deform in high temperature liquids
(d) Ceramic spoon can withstand breaking if dropped on the floor
Question.4. A student collected a sample of soil with dried twigs, small pebbles and dead leaves. He then added a few scoops of the sample into a beaker filled with water and stirred vigorously. He left the beaker undisturbed and observed it after 2 hours. Which of the following would be a correct observation?
(a) Soil dissolves in water and makes it muddy
(b) Dried twigs sink to the bottom of the beaker
(c) Soil and pebbles settle at the bottom of the beaker
(d) Dead leaves and pebbles remain afloat in the water
Ans.3. (c) Plastic spoon could deform in high temperature liquids
Ans.4. (c) Soil and pebbles settle at the bottom of the beaker
Hint: Observe the appearance of materials in order to differentiate them on the basis of lustre.
Question.5. Which of the following objects would show lustre?
(a) Earthen pot
(b) Plastic bottle
(c) Aluminium foil
(d) Wooden plank
Question.6. Some materials are naturally lustrous while others are coated with compounds to make them appear lustrous. Over time, all materials tend to lose lustre due to their environment.
Which of the following objects cannot regain their lustre upon being rubbed with sandpaper?
(a) Rusted nails
(b) Old silver cutlery
(c) Dusty ceramic mug
(d) Tarnished copper jug
Ans.5. (c) Aluminium foil
Ans.6. (c) Dusty ceramic mug
Hint: Examine materials by compressing or scratching them in order to categorize them as hard and soft material.
Question.7. Four baskets filled with different objects were placed in front of a classroom. Each student was asked to compress the objects to examine the hardness or softness and arrange them in order from hardest to softest. The contents of the four baskets were:
1. Styrofoam
2: Flour dough
3. Wooden blocks
4. A bunch of cotton
What would be the correct order?
(a) 3,1,2,4
(b) 3,1,4,2
(c) 2,3,4,1
(d) 2,3,1,4
Question.8. A person says that a kitchen sponge is harder than a lump of cotton and a plastic bottle is softer than a ceramic bottle. On examining these materials, what can be correctly said, about them?
(a) It is easier to break plastic bottles than to break ceramic bottles
(b) It is easier to compress cotton than to compress a kitchen sponge
(c) It is easier to stretch ceramic bottles than to stretch plastic bottles
(d) It is easier to tear up a kitchen sponge than to tear up a lump of cotton
Ans.7. (a) 3,1,2,4
Ans.8. (b) It is easier to compress cotton than to compress a kitchen sponge
Hint: Observe the change in the shape of object added to water in order to categorize them as soluble and insoluble materials.
Question.9. When a small amount of soil and pebbles are added to a beaker containing water and stirred well, it first forms a light brown liquid in which pebbles settle at the bottom. After half an hour, the soil is also observed to be settled at the bottom and the water above it appears clearer in the beaker. What conclusion can be made from this observation?
(a) Both, soil and pebbles are soluble in water
(b) Both, soil and pebbles are insoluble in water
(c) Soil is insoluble in water, but pebbles are soluble
(d) Pebbles are soluble in water and soil is insoluble
Question.10. A spoonful each, of sawdust, powdered sugar and salt were added to a glass containing water. Which of the following can be observed?
(a) Salt and sawdust are soluble in water, but sugar is insoluble
(b) Salt and sugar are soluble in water, but sawdust is insoluble
(c) Sugar and sawdust are soluble in water, but salt is insoluble
(d) Sugar, sawdust and salt are all soluble in water
Ans.9. (b) Both, soil and pebbles are insoluble in water
Ans.10. (b) Salt and sugar are soluble in water, but sawdust is insoluble
Hint: Plan and conduct an investigation for various objects to classify them based on whether the object sink or float in water.
Question.11. A stone, a small piece of wood and a metallic coin of the same weight were dropped in a bucket of water. Which of these would sink or float?
(a) The stone would sink, while the wood and coin would float
(b) The wood and stone would sink, while the coin would float
(c) The stone and coin would sink, while wood would float
(d) The stone, coin and wood, would all sink down
Question.12. An empty metallic bottle, glass bottle and plastic bottle, each of same size were lowered by applying similar force, into a bucket filled with water. What will happen when the force is removed?
(a) Metal bottle will float upwards and the others will stay at the bottom
(b) Plastic bottle will float upwards and the others will stay at the bottom
(c) Glass bottle will float upwards and the others will stay at the bottom
(d) All three kinds of bottles will slowly begin to float upwards
Ans.11. (c) The stone and coin would sink, while wood would float
Ans.12. (b) Plastic bottle will float upwards and the others will stay at the bottom
Hint: Classify objects into opaque, transparent and translucent.
Question.13. Students were asked to examine different materials and substances. These were, butter paper, aluminium foil, cardboard, white cotton cloth, frosted glass and water.
Which of the following is a correct observation?
(a) Only cardboard is opaque
(b) Only water is transparent
(c) Butter paper and water are translucent
(d) Aluminium foil, frosted glass and cotton cloth are opaque
Question.14. A source of light was observed, through three sheets of paper. These were,
Sheet 1: Butter paper
Sheet 2: White tissue paper
Sheet 3: Paper painted with black acrylic paint.
Which of the following is a correct statement regarding these sheets of paper?
(a) 1 is translucent, 2 is transparent and 3 is opaque
(b) 1 is transparent while 2 and 3 are translucent
(c) 1 is translucent while 2 and 3 are opaque
(d) 1 and 2 are translucent while 3 is opaque
Ans.13. (b) Only water is transparent
Ans.14. (d) 1 and 2 are translucent while 3 is opaque
