Please select a subject first
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Give a reason for the following statement :
The filter paper made into a cone & placed in a funnel for filtering out the solid particles in a solid-liquid mixture should be moistened before placing it.
Concept: undefined >> undefined
Give a reason for the following statement :
Brass & bronze are examples of mixtures, while copper sulphate & lead nitrate are examples of compounds.
Concept: undefined >> undefined
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Tick the most appropriate answer
2. Melting of ice is a
- reversible change
- irreversible change
- chemical change
- none of these
Concept: undefined >> undefined
Choose the most appropriate answer.
Rising and setting of the sun at a given place is a
Concept: undefined >> undefined
Tick the most appropriate answer.
3. Physical changes are
- permanent.
- periodic,
- temporary
- irreversible.
Concept: undefined >> undefined
Tick the most appropriate answer.
4. Chemical changes involve
- change in shape.
- change in size.
- change in molecular composition.
- none of these
Concept: undefined >> undefined
Tick the most appropriate answer.
5. Photosynthesis requires
- heat energy.
- wind energy
- sunlight.
- sound energy
Concept: undefined >> undefined
Fill in the blank
change in which the substance can be brought back to its original state is called a ............... change.
Concept: undefined >> undefined
Fill in the blank.
Changes that occur in nature are called ........................
Concept: undefined >> undefined
Fill in the blank.
An earthquake is a .................. change.
Concept: undefined >> undefined
Fill in the blank.
A new substance is formed in a ............... change.
Concept: undefined >> undefined
Fill in the blank.
Heat is .................... by a gas during the process of condensation.
Concept: undefined >> undefined
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 |
Concept: undefined >> undefined
Write true or false for the statement.
Burning of paper and formation of curd are reversible changes
Concept: undefined >> undefined
Write true or false for the statement
A natural change can also be a desirable change
Concept: undefined >> undefined
Write true or false for the statement.
Deforestation is a man-made change
Concept: undefined >> undefined
Write true or false for the statement
Decomposition of leaves is a fast change.
Concept: undefined >> undefined
Write true or false for the statement.
Dissolving of solute in a solvent and rusting of iron are both physical changes.
Concept: undefined >> undefined
Dissolving salt in water is a reversible change.
Concept: undefined >> undefined
Ripening of fruits is a desirable change.
Concept: undefined >> undefined
