classs 6(New Science Ahead)

3. •Weather and temperature
change.
•Softening of vegetables when
cooked
•Drying of wet clothes.
•Spoilage of food
•Rusting of iron

4. List out more changes.
1. Change in age
2. Changes in appearance
3. Growth of hair
4. Baking of bread
5. Growth of plants
6. Destruction of forest
7. Condensation and evaporation
8. Pollution of air
9. Falling of leaves
10. Flowering of plant
11. Movements of Earth
12. Changes of seasons

8. Examples
1. Melting of wax
2. cooling of water
3. boiling of water
4. folding of paper
5. evaporation
6. drying of clothes
7. BLOWINGA BALLOON
8. DISOLVING SALTINTOWATER
9. SHUFFLINGOF CARDS
10. MIXINGOF SANDAND IRON
11. CUTTINGOF HAIR

11. Examples
1. Burning of matchstick
2. Burning of wood
3. Burning of paper
4. Passage of time
5. Broken cupboard
6. Breaking of glass
7. Extraction of petroleum
8. Changes in appearance
9. Growth of plant
10. Sharpening of pencil
11. Spoilage of food
12. Cutting of vegetables
13. Baking of bread
14. Changing milk into curd
15. Rusting of iron

12. 1.Stretching of rubber band
2.Burning of paper.
3.Washing of clothes.
4.Breaking of glass
5.Rusting of iron.

17. 1. A physical change effects only physical properties.
2. The molecules of the substance involved do not
change.
3. No new substance is formed.
4. Physical change can be reversible or irreversible.
5. The amount of energy required to carry out a
physical change is small compared to amount
needed for chemical change.

18. https://www.youtube.com/watch?v=PR
OpBsX5KiE

19. https://www.youtube.com/watch?v=fyX81t2k66E

25. 1.Melting of wax- physical
change
2.Burning of wax- chemical
change- carbon dioxide+
soot + water(products)

28. An iron nail left out in
moist air rusts. Rusting is a
chemical change in which
iron reacts with oxygen and
forms rust (iron oxide).
Since a new substance is
formed, rusting is a
chemical change.

29. More examples of chemical change
1. Cooking of food
2. frying an egg
3. digestion of food
4. souring of milk
5. mixing acid and base
6. baking a cake
7. sugar to caramel
8. sugarcane to sugar
9. Fireworks
10. Jute to thread
11. Lighting of matchstick

30. Vinegar + baking soda Carbon dioxide
https://www.youtube.com/watch?v=LR5TNtznOfA&
pp=qAMBugMGCgJhchAB

32. 1. A chemical change is a result of
chemical reaction between reactants to
form one or more products.
2. New substances with different
properties are formed.
3. Chemical changes are mostly
irreversible in nature.
4. The amount of energy involved in a
chemical change is substantial.