Advertisements
Advertisements
Question
Change is the law of nature and occurs in our everyday life, at all times and in all places. Differentiate between the following change with a suitable example.
Desirable and undesirable change.
Solution
| Desirable change | Undesirable change |
| (i) Changes brought about by nature or man which produces – useful or good results. | (i) Changes brought about by nature or man which produces – useless or bad results. |
| (ii) Positive and advantageous nature. | (ii) Negative and detrimental nature. |
| (iii) Examples of a desirable change: Rain bringing water to the crops, change of milk to curd, ripening of fruits seedling into a plant. |
(iii) Examples of an undesirable change: Rain causing destruction by floods, milk turning sour on a hot day, rotting of fruits, cutting of trees. |
APPEARS IN
RELATED QUESTIONS
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 |
Ripening of fruits is a desirable change.
Define physical change. Give two examples for the above changes.
State whether the following is physical or chemical changes.
heating a mixture of iron filings and sulphur—
State whether the following is physical or chemical changes.
mixing oil with water —
Write true or false
Earthquake is a desirable change.
Tick (√) the correct alternative from the choice given for the following statement
Which one of the following is volatile in nature ?
Which of the following are physical changes and which are chemical changes?
Burning of candle wax, Melting of candle wax, Mixing of iron filings and sand, Burning of wood, Breaking a piece of chalk, Burning a piece of paper, Cutting a piece of paper.
Fill in the blank.
There is no change in the _____________of the substance during a physical change.
A physical change is generally____________.
