Question

Give 2 examples of following changes
1. Slow and fast change
2.natural and man made
3. Periodic and non periodic
4. Reversible and Irreversible
5. Physical and Chemical​

Answer 1

Answer:

1 Rusting of Iron

2 Burning of fuels and chemical reaction

3 I don't know

4 Reversible changes few example - melting of wax , freezing of ice

Irreversible change few example - burning and cooking

5 physical change few example - freezing of water, melting of wax

chemical change few example - digestion of food, burning of coal

Answer 2

Answer:

Slow change : Rusting of iron, fruits ripening and growing of trees.

Fast change : Crackers burst, blowing of balloons and burning of papers.

Natural Changes : Growth of the Human Body, Change in seasons.

Man made : Conversion of metals into alloys, Burning of fuel, Cutting of trees.

Periodic Changes : A pendulum swinging, The sun rises and falls, Modification of seasons.

Non periodic : Occurrence of earthquake, accidents, sneezing, rusting of iron, growing of a tree.

Reversible changes : Melting of ice, Boiling of water, Melting of wax, Stretching of a rubber band, Stretching of a spring.

Irreversible changes : Burning of fuels (like Wood, Coal and LPG), Cooking of food, Rusting of iron , Grinding of wheat grains into flour, Baking of chapatti (roti), Growth of a plant.

Physical changes : Cutting, bending, dissolving, freezing, boiling, and melting

Chemical changes : Rusting of iron in presence of moisture and oxygen, Burning of wood, Milk becoming curd, Formation of caramel from sugar by heating, Baking of cookies and cakes.