Advertisements
Advertisements
प्रश्न
Which of the following are physical changes and which are chemical changes ?
Rusting of iron
पर्याय
Physical change
Chemical change
Advertisements
उत्तर
Rusting of iron – Chemical change
APPEARS IN
संबंधित प्रश्न
Classify the following as chemical or physical change:
Melting of butter in a pan
Tick the most appropriate answer.
3. Physical changes are
- permanent.
- periodic,
- temporary
- irreversible.
What role does energy play in initiating a chemical change ?
State whether the following is physical or chemical changes.
photosynthesis —
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.
Potassium chloride is added to water and stirred. A salt solution is obtained, which is then boiled, leaving behind a residue.
- Is the above change physical or chemical?
- Name the residue which remains behind after the salt solution is boiled.
- Is the change reversible or not reversible?
- Are the composition and properties of the original substance altered?
- Give a reason why the above experimentation would not be possible if calcium carbonate was taken in place of potassium chloride.
Give a reason why – Heating a platinum wire is a reversible change but, heating a magnesium wire is an irreversible change.
Select the chemical changes from the following list of changes
Rotting of eggs.
Name the following.
A form of energy required for a chemical change.
Ice, water and water vapour look different and display different ______ properties but they are ______ the same.
