Question

A change that cannot be reversed is called ________ change, while the change which can be reversed is called _______ change.

• A. slow, fast
• B. permanent, temporary
• C. natural, man-made
• D. natural, permanent

Answer 1

The correct option is B permanent, temporary

The changes which occur for some definite amount of time and can be reversed are called temporary changes. For example, melting of ice is a temporary change as water which is obtained after melting of ice can be converted back to ice on freezing.

The changes which cannot be reversed are called permanent changes. For example, burning of paper is a permanent change as the ash obtained after burning the paper cannot be converted back to paper again.