OpenOlympiad
Concept 2 of 8Foundation
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Reversible vs irreversible

Reversible: can be undone. The substance returns to its original form.

  • Ice ⇄ water ⇄ vapour (states of water)
  • Stretching a rubber band
  • Rolling a dough ball flat and back
  • Switching a fan on/off

Irreversible: cannot be undone.

  • Burning wood (ash can't become wood)
  • Cooking an egg
  • Rusting of iron
  • Ripening of fruit
  • Paper torn
Example
Cutting a cake = irreversible (pieces can't become whole).
Folding paper = reversible.
💡 Tip:If you can easily return to the original, it's reversible. Otherwise irreversible.
Prefer a video? Open YouTube search for “reversible irreversible changes class 6

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5 questions to check what you just read.

0 / 5
  1. Q1.Reversible:
  2. Q2.Irreversible:
  3. Q3.Water ⇌ steam is:
  4. Q4.Tearing paper is:
  5. Q5.Switching on a fan then off: