Advertisements
Advertisements
Question
Assertion: The explosion of fire cracker is a physical change.
Reason: A physical change is a reversible change.
Options
Both A and R are true and R is the correct explanation of A.
Both A and R are true but R is not the correct explanation of A.
A is true but R is false.
A is false but R is true
Advertisements
Solution
A is false but R is true
APPEARS IN
RELATED QUESTIONS
Fill in the blank.
Heat is .................... by a gas during the process of condensation.
Match the columns
| column A | coulmn B |
| 1. A change which cannot be easily reversed | a. man-made change |
| 2.A change that repeats itself at regular intervals | b. chemical change |
| 3. A change that is made by humans | c. physical change |
|
4. A change in which the original substance cannot be obtained |
d. periodic change |
| 5. A change where no new substance is formade | e. irreversible change |
| f. slow change |
State three differences between evaporation and boiling
Fill in the blank
Chemical change occurs as a result of __________ between two substances.
Write true or false
Earthquake is a desirable change.
Give two examples of periodic changes.
Solve this crossword by using the clues that follow-

Across
1. Energy in the form of sunlight is absorbed by the green plants in this process.
4. The reddish-brown substance formed over iron in the presence of oxygen and moisture.
5. This change is permanent and irreversible.
6. The process in which a solid directly changes into gaseous state.
Down
1 . It is the change that takes place in case of swinging pendulum of a clock. –
2. Occurrence of this is a non-periodic change as well as a natural change.
3. It is a physical change.
Which of the following are chemical changes ?
- decaying of wood
- burning of wood
- sawing of wood
- hammering of nail into wood
Differentiate between a physical change and a chemical change with reference to – Energy change taking place during the respective change.
The change of state of a substance from solid to liquid and liquid to gas is ______.
