Page 45 - ICSE Chemistry 8

Review Your Learning

A. Answer in one word/a few words.
1. A change in which we can get back the original substance by reversing the ac on ______________
2. A non-periodic change ______________

3. An undesirable change ______________
4. A change which is temporary and reversible ______________
5. A chemical change ______________

B. State whether the given statements are true (T) or false (F).
1. Changes that are benefi cial to us are called desirable changes.

2. Burning of paper is a physical change which is slow.
3. Glowing of an electric bulb on the passage of electric current is a chemical change.
4. Evapora on is a physical change.
5. Diges on of food is a chemical change that involves release of energy.

C. Explain the following terms.
1. Fast change

2. Natural change
3. Evapora on
4. Condensa on
5. Sublima on
6. Rus ng

D. Answer the following ques ons.

1. Diff eren ate between reversible and irreversible changes.
2. What is a physical change? Write characteris cs of a physical change. Give examples of a physical
change.
3. What is the diff erence between evapora on and boiling?
4. What is sublima on? Discuss sublima on of ammonium chloride.
5. What is a chemical change? Write characteris cs of a chemical change. Give examples of a chemical
change.
6. Write about the changes in which energy is released or absorbed.

PROJECT
Create a PowerPoint presenta on on the topic ‘Useful Physical and Chemical Changes’. Find the related
informa on and images using the Internet. Add audio and visual eff ects to your presenta on. Format it as
per your choice.

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