Select the chemical changes from the following:
(i) Digestion of food
(ii) Boiling of water
(iii) Cooking of food
(iv) Tarnishing of silver spoon
(v) Sublimation of iodine
(vi) Electrolysis of water
(vii) Melting of butter in a pan
(viii) Burning of wood
The chemical changes from the following are -
(i) Digestion of food:
(ii) Cooking of food:
It is a chemical change because after cooking the food, the raw ingredients or the vegetables cannot be regained again.
(iii) Tarnishing of silver spoon:
(iv) Sublimation of iodine:
(v) Electrolysis of water:
(vi) Burning of wood:
The physical changes are
(vii) Boiling of water:
During boiling, water changes from liquid to a gaseous state, and on cooling the gaseous state or vapours can be converted back to the water. So a new product is formed.
(viii) Melting of butter in a pan:
Melting of butter only changes the shape of butter from solid to liquid. On cooling, it can return to its original shape