5. Heat is evolved/absorbed.
F.
Classify the following as physical and chemical changes:
1. Burning of magnesium ribbon
2. Rusting of iron
3. Burning of candle
4. Twinkling of stars
5. Cooking of food
chemical c
Chemical
Chemical a
Physical
physieat an
6. Melting of wax [NCERT]
7. Boiling of water
8. Cutting of fruits
s physical
9. Photosynthesis [NCERT]
Answers
Answer:
heat is absorbed
1.chemical change
2.Chemical change
3Chemical change
4.Chemical change
5.chemical change
6.Chemical change
7.Physical change
8.Chemical change
9.Chemical change
Answer:
5) A chemical or physical reaction is endothermic when heat is absorbed. A chemical or physical change is exothermic when heat is released.
F. 1) Chemical change
2)Chemical change
3)Physical as well as chemical change
4)Physical change
5)Chemical change
6)Physical change
7)Physical change
8)Chemical change
9)Chemical change
Explanation:
F. 3) On burning candle wax melts, which is a physical change. Also, the wax near the flame burns and gives CO2, soot, light and heat which is a chemical change. Hence, burning of a candle is both physical as well as a chemical change.