1. Raw egg to boiled egg.
2. Batter to idli.
3. Wet clothes to dry clothes.
4. Woollen yarn to knitted
sweater.
5. Grain to its flour.
6. Cold water to hot water.
7. Straight string to a coiled string.
8. Bud to flower.
9. Milk to Cheese.
10. Cowdung to biogas.
II. Ice cream to melted ice-cream.
12. Stretched rubber band to
its normal size.
13. Souring of milk.
14. Ripening of a mango.
15. Dissolving sugar in water.
these are reversible or Irreversible, chemical or physical, Natural or manmade, periodic or non periodic,desirable or undesirable?