Advertisements
Advertisements
प्रश्न
Explain why burning of wood and cutting it into small piece are considered as two different types of changes.
Advertisements
उत्तर
- Wood cannot be joined again to form the original piece, but its properties do not change.
- This is a physical change. Wood cannot be restored to its original form after burning.
- Its properties also change, and heat is produced. This is a chemical change. Here, there are two different states of burning the wood and cutting it into small pieces.
- In this situation, two different types of changes are considered.
APPEARS IN
संबंधित प्रश्न
State whether the following statement is true or false. In case a statement is false, write the corrected statement.
Cutting a log of wood into pieces is a chemical change.
When a candle burns, both physical and chemical changes take place. Identify these changes. Give another example of a familiar process in which both the chemical and physical changes take place.
Tick the most appropriate answer
2. Melting of ice is a
- reversible change
- irreversible change
- chemical change
- none of these
Tick the most appropriate answer.
Photosynthesis requires
Fill in the blank
Changes that occur in nature are called ______
Classify the following as physical or chemical change :
Growth of a plant
Give four difference between physical and chemical changes.
Name the following.
The product obtained during a physical change when water converts from a liquid into a solid.
Classify the following as physical or chemical properties
The composition of a sample of steel is 98% iron, 1.5% carbon and 0.5% other elements.
Match the items of Column I with the items of Column II.
| Column I | Column II | ||
| (a) | Large crystals | (i) | Turns lime water into milky |
| (b) | Depositing a layer of zinc on iron | (ii) | Physical change |
| (c) | Souring of milk | (iii) | Rust |
| (d) | Carbon dioxide | (iv) | Sugar candy (Mishri) |
| (e) | Iron oxide | (v) | Chemical change |
| (f) | Dissolving common salt in water | (vi) | Galvanisation |
