Permanent Change

Q.

Which of the following are chemical changes?
(i) Decaying of wood
(ii) Burning of wood
(iii) Sawing of wood
(iv) Hammering of a nail into a piece of wood

1. (i) and (ii)

2. (ii) and (iii)

3. (iii) and (iv)

4. (i) and (iv)
   

Q.

Is tearing of paper a reversible change or irreversible change

Q.

What happens when vinegar is mixed with bicarbonate of soda? Can you get vinegar and the bicarbonate back from the resultant mixture? Why? [3 MARKS]

Q. Is burning of petrol a physical change ?
No , Why?

Q. Is cutting or tearing of paper reversible or irreversible.
if reversible how can we reverse it?
Name the process and explain it.

Q.

Is deforestation a reversible change? Why or why not? [1 MARK]

Q. Digestion of food is a

1. Reversible

2. Irreversible

3. where there is no alteration in state.

4. Both reversible and irreversible

Q. What is the change taking place in the following processes ?

1. Irreversible, chemical change
2. Reversible, physical change
3. Irreversible, physical change
4. Reversible, chemical change

Q. Changes which occurs naturally are called __________ changes.

1. man-made
2. chemical
3. natural
4. irreversible

Q.

Those phenomena which happen on their own in nature is called as ___ phenomenon.

1. man-made

2. irreversible

3. natural

4. reversible

Q.

Periodic changes:

1. do not repeat themselves
2. are irreversible changes
3. repeat at regular intervals
4. repeat at irregular intervals

Q. The changes which are not harmful to our environment are known as :

1. Desirable change
2. Undesirable change
3. Man-made change
4. Natural changes

Q. ___________ of iron is irreversible change

Q. Burning is a/an change.

1. reversible
2. irreversible
3. temporary

Q. tearing of paper is said to be a change that cannot be reversed.
Is this statement true or false.

Q. Adi wrapped some pulses in a wet cotton cloth and when he observed it after a few days, he found small sprouts on them. What kind of change could this be?

1. Physical
2. Reversible
3. Irreversible
4. Periodic

Q. Which amongst the following changes involves the change in composition?

1. Melting of ice
2. Burning of wooden logs
3. Boiling of water
4. Cutting of wooden logs

Q. when we burn a plastic bottle and wood is it physical or chemical change

Q. Define the term IR rersible change in easy language

Q. Which of the following is a physical but irreversible change?
(a) burning of matchstick
(b) melting of ice cream
(c) breaking of a flower vase
(d) lighting of an electric bulb

Q.

E) Give an example of each type of change

3) A slow change

Q. The following changes are examples of ________ change.

1. 
2. 
3. 
4. 

Q.

1.Can we reverse the following change? If yes, suggest the name of the method.

(b) Water vapour into water

Q. Conversion of milk into curd is an irreversible change.

1. False
2. True

Q. Identify the incorrectly classified changes from the given table.​

1. I and IV​
2. II and IV
3. I and III
4. I, II and III

Q.

The figure shows what type of change?

1. Permanent

2. Temporary

3. Both temporary and permanent

4. No change

Q.

Which of the following changes are irreversible in nature?

1. Setting of cement

2. Melting of candle wax

3. Dissolution of sugar in water

4. Burning of a candle

Q. Is change of state of physical change or a chemical change?

Q. The following image shows :

1. Man-made change
2. Physical change
3. Desirable change
4. Undesirable change

Q. The conversion of potato to potato wafers is a/an _______ change.

1. reversible
2. temporary
3. irreversible
4. natural