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.
Advertisements
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
State three differences between evaporation and boiling
State whether the following is physical or chemical changes.
burning of sugar —
Write true or false
Cutting of paper into pieces is a chemical change.
Fill in the blank
Heat is ________ by a gas during the process of condensation.
State why addition of sodium chloride to water is considered a physical change, while addition of dilute sulphuric acid to zinc is considered a chemical change.
Give reasons why – separation of mixtures e.g. iron from a mixture of iron and sulphur is a physical change, but heating a mixture of iron and sulphur is considered a chemical change.
Give a reason why
Change of seasons is a periodic change while the change of weather is a non-periodic change.
Give the reason why the following is considered as chemical changes.
Copper carbonate on heat gives copper oxide and carbon dioxide.
What type of energy changes is associated when ice melts?
The change of state of a substance from solid to liquid and liquid to gas is ______.
