Advertisements
Advertisements
प्रश्न
Change is the law of nature which occurs in everyday life.
State when a substance [i.e. matter] undergoes a kind of change.
Advertisements
उत्तर
Change is the law of nature that occurs in everyday life. A substance [i.e. matter] undergoes a kind of change when subjected to energy changes.
The matter is said to undergo certain changes when energy is added to the matter or removed from the matter.
Examples of Changes are:
- Ice melts on supplying heat to it.
- Milk changes into curd when a little curd is added to hot milk.
APPEARS IN
संबंधित प्रश्न
Tick the most appropriate answer.
5. Photosynthesis requires
- heat energy.
- wind energy
- sunlight.
- sound energy
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
Fill in the blank
Revolution of the earth around the sun is a ________ change.
True or false
In a physical change no net energy change is involved.
Separate the following into physical and chemical changes :
Sublimation of a solid, Decomposition of water into hydrogen and oxygen by passing electric current, Formation of clouds, Making a fruit salad from raw fruits, Dissolving carbon dioxide in water
Which of the following are physical changes and which are chemical changes ?
Freezing of water
Fill in the blank.
A change, which alters the composition of a substances, is known as a___________ change.
State why addition of sodium chloride to water is considered a physical change, while addition of dilute sulphuric acid to zinc is considered a chemical change.
Digestion of food is a physical change.
Explain the characteristics of physical change with examples.
