Give an example of a physical change in which the colour of the substance changes.

_________ is an example of a periodic change.

State two examples of periodic changes.

Give an example to justify the statement that physical changes can be reversible as well as irreversible.

Give an example of motion where there is a change only in speed but no change in direction of motion.

"_________" is a physical change.

Boiling of water is a physical change, but boiling of egg is a chemical change. Why?

How can a change occur in a substance?