Physical and Chemical Change CHEMISTRY - Physical and Chemical Change

When we add water to the following substances, which one will show a chemical change?

A pop sound is heard when a lighted match stick is brought near the mouth of a jar. This indicates the release of gas.

When sugar is heated, its colour changes into

The compound rust is a hydrated oxide of

An example of both physical and chemical change is

State whether the following is physical or chemical changes.
Slaking of lime —

State whether the following is physical or chemical changes.
Boiling of an egg —

State whether the following is physical or chemical changes.
Melting of wax —

State whether the following is physical or chemical change.
Digestion of food —

State whether the following is physical or chemical changes.
photosynthesis —

Define a chemical change. Give two examples of the above changes.

Define physical change. Give two examples for the above changes.

What role does energy play in initiating a chemical change ?

How do you say that the process of digestion is a chemical change ?

A physical change is temporary. Explain.

A burning candle shows both physical and chemical changes. Explain ?
Burning of a candle is both a physical and chemical change.

Mention a change which is always

What are reversible and irreversible changes ? Give one example for each.
Change is the law of nature and occur in our everyday life, at all times and in all places.
Differentiate between the following change with a suitable example.
Reversible and irreversible change.

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.

Name a chemical change which takes place in presence of:

State four differences between physical and chemical changes.

State three differences between evaporation and boiling

Make a list of different types of changes with example.

State the various conditions that favour the process of evaporation.

Growing of a seedling into a plant is _______ change.

Revolution of the earth around the sun is a ________change.

Burning of fuel is a _______ change.

Chemical change occurs as a result of _________between two substances.

When a candle burns, wax melts. Melting of wax is a________ change.

Burning of sugar is a temporary change.

Melting of ice is a physical change.

Earthquake is a desirable change.

Rusting of iron is a chemical change.

Cutting of paper into pieces is a chemical change.

Column A	Column B
(a) Evaporation of water	(i) Non-periodic change
(b) Milk turning sour	(ii) Periodic change
(c) Earthquake	(iii) Chemical change
(d) Change of seasons	(iv) Physical change
(e) Glowing of bulb	(v) Reversible change