CBSE Class 8 Science Chapter 4 Combustion And Flame Activities

CBSE Class 8 Science Chapter 4 Combustion And Flame Activity Ideas Activity 1

Aim: To show that the quality of the burning flame depends on the amount ofair available around it.

Materials Required: A candle, a glass chimney, a few wooden blocks and a glass plate.

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Procedure:

• Fix a lit candle on a table.
• Put a glass chimney on the candle.
• Rest this arrangement of the chimney on the wooden blocks.
• Make sure that air can enter the chimney
• Remove the wooden blocks and let the chimney rest on the table.
• Finally, put a glass plate over the chimney
• Note the observations.

Observation: When the chimney is on wooden blocks, the candle burns freely as the air enters the chimney. When the wooden blocks are removed, the air does not enter the chimney.

Due to this, the candle starts to produce smoke. You will also observe the flame of a candle flickering. Now, when we put the glass plate over the chimney, the flame finally goes.

Conclusion: We can conclude that air is necessary for burning. Partial availability ofair causes the smoke to be produced. Complete lack ofair causes the flame to go off.

Class 8 Science Chapter 4 Combustion And Flame Hands-On Experiments Activity 2

Aim: To show the supply of oil needed for combustion.

Materials Required: A Piece of wood or charcoal, an Iron plate or tawa, a glass jar or a transparent plastic jar.

Procedure:

1. Place a piece of burning wood or charcoal on the Iron plate or tawa.
2. Cover it with the glass jar or the transparent plastic jar.
3. Note the observation.

Observation: Wood or charcoal burns under the jar and continues burning for some time. But, after some time burning stops.

Conclusion: Wood and charcoal stop burning after they are covered with a glass or transparent plastic jar, which shows that air is necessary for combustion.

CBSE Class 8 Science Chapter 4 Combustion And Flame Simple Experiments Activity 3

Aim: To show that ignition temperature is essential for substances like paper to burn.

Materials Required: A Sheet of paper, water and candles.

Procedure:

1. Make two paper cups by folding a sheet of paper.
2. Pour about 50 ml of water into one of the cups.
3. Heat the cups separately with the help of a candle.
4. Note your observations.

Observation: We see that the empty paper cup catches fire easily and starts burning. On the other hand, the paper cup containing water does not catch fire. The water in the cup becomes hot gradually. If continued heating, water will start even boil in the paper cup.

Conclusion:

• When we heat an empty paper cup, its ignition temperature is reached quickly. It catches fire and starts burning.
• When we heat the paper cup having water, the heat is transferred to the water by conduction. The Ignition temperature of paper is not reached, and hence, it does not burn.
• This shows that ignition temperature is essential for a substance to burn.

Class 8 Science Chapter 4 Combustion and Flame Activity With Step-By-Step Guide Activity 4

Aim: To show that the innermost zone of a candle flame consists of unburnt wax vapour.

Materials Required: A candle, a glass tube, a pair of tongs and a matchstick.

Procedure:

1. Light the candle carefully.
2. Hold the glass tube with a pair of tongs.
3. Introduce one end of the glass tube in the dark zone of a non-flickering candle flame.
4. Bring the lit matchstick near the other end of the glass tube as shown in the figure given above.

Note your observations.

Observation: When a lit matchstick is brought near the other end ofthe glass tube, we observe a flame at this end. It is because the innermost zone (dark zone) of the candle flame consists of unburnt wax vapours. Some vapours from it enter the glass tube. When the lit matchstick is brought near it, the wax vapours start burning and produce a flame.

Conclusion: A flame burns at the other end of the glass tube when a matchstick is lit near it. Hence, we can conclude that the innermost zone (dark zone) candle flame has unburnt wax vapours.

Activity 5

Aim: To show that the middle zone of a candle flame consists of unburnt carbon particles.

Materials Required: A candle, a glass plate, and a pair of tongs.

Procedure:

1. Light the candle.
2. Hold the glass plate with a pair of tongs as shown in the figure.
3. Introduce the glass plate in the middle zone.
4. Hold it for 10 seconds and then remove.

Note the observation.

Observation: When the glass plate is kept over the middle zone of the flame, a blackish circular ring is formed. The blackish ring is produced due to the deposition of unburnt carbon particles present in the luminous zone of the flame.

Conclusion: The observation concludes that the partial combustion of wax vapours in the luminous zone produced unburnt carbon particles.

CBSE Class 8 Science Chapter 4 Combustion And Flame Activity With Observation Notes Activity 6

Aim: To show that the outermost zone of a flame is the hottest

Materials Required: A copper wire, a pair of tongs and a candle.

Procedure:

1. Take a copper wire.
2. Hold it’s one end with a pair of tongs.
3. Introduce its other end just inside the flame (outermost zone) for about 30 seconds.

Note the observation.

Observation: We observe that the portion of the copper wire just inside the flame gets red hot.

Conclusion: The observation concludes that the outermost, non-luminous zone of the flame has a high temperature. Hence, it is the hottest part of the flame.