Advertisements
Advertisements
प्रश्न
State one instance where water undergoes a physical change and one in which it undergoes a chemical change.
Advertisements
उत्तर
Water undergoes a physical change when it is heated to a temperature of 100°C. At this temperature, the water gets converted to water vapours. This process is called evaporation. Water undergoes a chemical change when it is subjected to electricity. It splits into its constituents, oxygen and hydrogen, by the process of electrolysis.
APPEARS IN
संबंधित प्रश्न
State three differences between evaporation and boiling
What do you observe when :
lighted match stick is brought near the mouth of the test tube containing hydrogen gas.
State whether the following is physical or chemical changes.
growing of a piglet into a pig —
Solve this crossword by using the clues that follow-
Across
1. Energy in the form of sunlight is absorbed by the green plants in this process.
4. The reddish-brown substance formed over iron in the presence of oxygen and moisture.
5. This change is permanent and irreversible.
6. The process in which a solid directly changes into gaseous state.
Down
1 . It is the change that takes place in case of swinging pendulum of a clock. –
2. Occurrence of this is a non-periodic change as well as a natural change.
3. It is a physical change.
Classify the following as physical or chemical change :
Formation of curd from milk
Classify the following as physical or chemical changes :
Breaking of a glass tumbler
Ice kept in a beaker, slowly melts and turns into water. The water in the beaker on solidification is freezing turns back to ice. Give four reasons why the change from ice to water and water back to ice is considered a physical change.
Assertion: The explosion of fire cracker is a physical change.
Reason: A physical change is a reversible change.
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.
Keeping a stone in sunlight for few hours is ______.
