Subjective Questions For Changes Around Us

SUBJECTIVE TYPE QUESTIONS

1. Milk can be changed into curd but curd cannot be changed back into milk. What is the general name of such changes ?
2. State whether burning of paper is a reversible change or an irreversible change.
3. Give one use of the expansion of an object on heating.
4. State five changes which are observed in our everyday life.
5. Give one example of a beneficial change and one example of a harmful change.
6. Give two examples of reversible changes.
7. Give two examples of irreversible changes.
8. Explain how, the iron blade of a spade is fixed to a wooden handle.
9. How do the following changes differ from one another ?
   1. Melting of wax
   2. Burning of wax
10. What is the difference between the following changes?
    1. Rolling of roti from dough
    2. Baking of roti
11. How do the following changes differ from each other ?
    1. Inflating a balloon
    2. Bursting an inflated balloon
12. When is a change said to have taken place in a material? Explain with the help of an example.
13. What is meant by ‘reversible changes’ and ‘irreversible changes’ ? Explain with examples.
14. Explain why, the burning of paper is said to be an irreversible change whereas the boiling of water is known as a reversible change.