i. Opaque is a materials through which you are not able to see.
ii. Insoluble substances mix in water.
iii. Soft materials can be compressed or scratched.
iv. Brick is opaque, while butter paper is translucent.
v. Salt does not dissolve in water.
vi. All gases are non–lustrous.
vii. Oil mixes with water.
viii. Stone settles down in water.
ix. Vinegar does not mix with water.
x. Iron is harder than sponge.
xi. Air is transparent.
xii. Glycerine is not soluble in water.
xiii. Diamonds, gems and pearls are lustrous.
xiv. Honey floats on the surface of water.
xv. Alcohol is immiscible with water.
xvi. Diamond is the hardest natural occurring substance.
i. gas is soluble in water.
ii. Grouping things together with similar properties is called .
iii. is the metal that exists in liquid state.
iv. is a soft metal that can be cut with a knife.
v. Iodine is a that has lustre.
vi. A piece of stone is a material.
vii. All gases are not in water.
viii. Dried leaf on the surface of water.
ix. Oily patch on a piece of paper is .
x. Water is a liquid.
xi. Materials that have lustre are usually called as .
xii. Materials are grouped on the basis of or in their properties.
Ans. similarities , dissimilarities
xiii. Based upon transparency, materials can be grouped as , and .
Ans. opaque , transparent , translucent
xiv. A substance which is used in making different objects is called .
Q4. Name a liquid which is lustrous?
Ans. Amongst the liquids, mercury is the lustrous.
Q5. Name two non-metals which are lustrous?
Ans. Graphite and Iodine crystals.
Q6. What happens when we add mustard oil to a glass full of water?
Ans. The mustard oil floats on water and forms a separate layer.
Q7. Name some materials that float on water?
Ans. wax, plastic ball, wood, leaf, ice, thermocol, oil.
Q8. Name some materials that sink in water?
Ans. stone, key, screw, iron nail, coin.
Q9. Name any two things which can be made out of wood?
Ans. Table and Chair.
Q10. Write the object from the following which shine: brick, earthen pitcher, glass bowl, plastic table, steel spoon, cotton bed sheet, newspaper.
Ans. glass bowl and steel spoon.
Q11. Make a list of items that floats on kerosene?
Ans. paper, thermocol, thin plastic sheet.
Q12. Name one lustrous material?
Q13. Which material is generally used for making pens?
Ans. Plastic or Metal.
Ans. Wooden doors and steel plate.
Q15. Define density. How is it related to floating and sinking in water?
Ans. The degree of compactness of a substance is called density. The object which is denser than water will sink whereas object which is less dense than water will float.
Q16. Write two things made from leather.
Ans. belt and hand-bag.
Q17. Write name of any three metals.
Ans. Iron, Aluminium and Copper.
Q18. Name few things made up of plastic.
Ans. cups, plates, toys, buckets, baskets.
Q19. Why water is considered as a universal solvent?
Ans. Water is capable of dissolving most of the substances in it. That is why it is known as universal solvent.
Q20. Why does a coin sink in water?
Ans. Object with higher density than water will sink. A coin is made up of metal. Density of metal is higher than water. That’s why coin sinks in water.