Dil. HCl is added to Zn granules. How will you prove that chemical change has taken place here? Support your response with two arguments.

State the post-fertilisation changes that lead to fruit formation in plants.

Why do arteries have thick and elastic walls whereas veins have valves?

The refractive indices of three media are given below:

A ray of light is travelling from A to B and another ray is travelling from B to C.

(a) In which of the two cases the refracted ray bends towards the normal?

(b) In which case does the speed of light increase in the second medium? Give reasons for your answer.