Advertisements
Advertisements
Question
Give the reason why the following is considered as chemical changes.
A bright light is seen evolved when a strip of magnesium is heated.
Advertisements
Solution
Magnesium is heated producing a bright light to form MgO in the air is a chemical change as the composition changes (MgO white powder) is formed, is irreversible. We cannot get magnesium back from MgO.
APPEARS IN
RELATED QUESTIONS
Define physical change. Give two examples for the above changes.
Classify the Following as a Physical Or a Chemical Change.
Making of a Sugar Solution
Change is the law of nature and occurs in our everyday life, at all times and in all places. Differentiate between the following change with a suitable example.
Desirable and undesirable change.
Differentiate between a physical change and a chemical change with reference to – Energy change taking place during the respective change.
Photosynthesis is a natural process by which green plants manufacture food in the presence of sunlight.
State the conclusions which can be drawn, to represent photosynthesis as a physical or a chemical change.
Match the following
| Sr. No. | A | B | C |
| 1. | Melting | Change of state from liquid to solid | Ticking of clock |
| 2. | Condensation | Change of state from liquid to gas | Formation of ice cube |
| 3. | Evaporation | Change of state from solid to liquid | Collecting flowers |
| 4. | Freezing | Change of state from gas to liquid | Ice cube to water |
| 5. | Periodic change | Occurs at irregular time intervals | Water to steam |
| 6. | Non-periodic change | Occurs at regular time intervals | Steam to water drops |
Higher order Thinking question
Boiling of water is a physical change; but boiling of egg is a chemical change. Why?
Which of the following is a physical change?
Grinding of wheat grain changes its size. It is a ____________ change.
Give an example to justify the statement that physical changes can be reversible as well as irreversible.
