OpenOlympiad
Concept 1 of 8Foundation
Video

Changes are everywhere

Nothing stays exactly the same. Change happens constantly — leaves turn yellow, ice melts, iron rusts, babies grow.

Scientists classify changes in four ways:

  • Reversible vs Irreversible
  • Physical vs Chemical
  • Fast vs Slow
  • Desirable vs Undesirable

A single change often belongs to several categories at once.

Example
Milk → curd: chemical, irreversible, slow, desirable.
Paper burning: chemical, irreversible, fast, undesirable (usually).
💡 Tip:Look for signs: new smell, new colour, gas evolved, heat given out, impossible to reverse → chemical.
Prefer a video? Open YouTube search for “changes around us class 6

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5 questions to check what you just read.

0 / 5
  1. Q1.A change we can undo is:
  2. Q2.A change we CANNOT undo:
  3. Q3.A paper burning is:
  4. Q4.A shirt drying after washing:
  5. Q5.Change categories include: