Question

Fill in the blanks

(a) Materials that do not allow light to pass through them are called ____.

(b) Metals have a shiny appearance called _____.

(c) Materials which can be pressed easily are called _____ materials.

(d) Copper and gold are _______.

(e) Dried leaves fallen on the surface of a pond _____ in the pond.

(f) ______ and ________ dissolves in water.

2. Fill in the Blank

a. Generally on heating metals ______ .

b. Paper, petrol, LPG, CNG etc. are _________ substances.

c. A change in which new substance is formed is called __________.

d. A change that occurs during a definite time interval is known as _________.

e. ______ is the process Heating of milk for boiling to kill microbes.

f. Dissolving sugar in water is a ____________.

g. water changes into ice on cooling is an example of _______.

h. Those changes which are desired to occur that is we want them to take place are known

_________.

3. Why metals often lose their shine and appear dull?

4. Select odd one out?

(a) Aluminium

(b) Iron

(c) Silver

(d) Sand

5. Find the odd one out from the following

(a) Tawa

(b) Spade

(c) Pressure cooker

(d) Eraser

6. Pick one material from the following which is completely soluble in water.

(a) Chalk powder

(b) Tea leavesAn iron nail is kept in each of the following liquids. In which case would it lose its shine and

appear dull?

(a) Mustard oil

(b) Soft drink

(c) Coconut oil

(d) Kerosene

8. P, Q and R are the three gaseous components of air. Gases P and Q can dissolve in the water

of rivers, lakes and seas but gas R does not dissolve in water. The organisms S which live in

water use the gas P dissolved in water to make their food by the process of photosynthesis. All

the organisms which live in water use the gas Q dissolved in water for releasing energy from

food. Gas R is the major component of air. (a) What are gases (i) P (ii) Q and (iii) R? (b) Name

the organisms S. (c) Name a gas like R which does not dissolve in water.

9. X, Y and Z are the three types of materials. The materials X and Y can break into pieces easily

when hit with an object but material Z does not break easily. The material X is used in the

windows of bathroom in our house whereas material Y is used in the windows of our drawing

room. The material Z is used in making doors and almirahs in our house.

(a) What do you think material X could be?

(b) What could material Y be?

(c) What could material Z be?

(d) What is the difference between X and Y?

10. A bag of cement lying outside in the open got wet due to heavy rain. Can we reverse the

change occurred to the cement by placing it under the sun?

11. Is burning of incense stick an irreversible change?

12. Why is metal rim heated before fixing on to wooden cart wheel?

13. Iron blade of tools has a ring in which the wooden handle is fixed. Why the ring is made

slightly smaller in size than wooden handle? please answer it fast ​

Answer 1

Answer:

(a) opaque

(b) lustre

(c) soft

(d) Metals

(e) floats