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Changes Around Us: Physical and Chemical

Burning needs air

An oil lamp burns in the open. A cover is put over the lamp. The flame goes out.

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The idea

An oil lamp burns. Fresh air reaches the flame.
Step 1 of 3
  1. An oil lamp burns. Fresh air reaches the flame.
  2. A cover goes over it. Fresh air stops coming in.
  3. After some time the flame goes out.

Combustion is burning. A substance joins with oxygen. Heat, light or both are given out.

Substances that burn this way are combustible substances. Dry grass, charcoal, candle wax and petrol are examples.

Magnesium is a silvery-white metal. It burns in air with a very bright light. Never look straight at it. Burning magnesium makes a white powder, magnesium oxide. Magnesium oxide is magnesium joined with oxygen.

Combustion needs a combustible substance and oxygen from the air. It gives out heat, light or both.

Because a covered flame gets no fresh air, the flame goes out.

Only an adult lights a flame. Stay well away from the flame.

Jump to lesson

This track

  1. 0 Start here
  2. 1 Fold it, cut it, crumple it
  3. 2 Ice, water and steam are one substance
  4. 3 Dissolving is not disappearing
  5. 4 Some of these will not go back
  6. 5 Checkpoint: changes that make nothing new
  7. 6 A test for something new
  8. 7 Five signs, and what each one is worth
  9. 8 One candle, two changes at once
  10. 9 Two questions, not one
  11. 10 Slow changes in rocks
  12. 11 Checkpoint: new substances and the two questions
  13. 12 Burning needs air
  14. 13 The fire triangle
  15. 14 A change written in words
  16. 15 Useful and harmful changes
  17. 16 Checkpoint: burning, equations and useful changes
  18. 17 The big picture
  19. 18 Track quiz

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