Explain why objects moving in fluids must have special shapes.

Explain why there is no waste in a forest

Explain why the planets do not twinkle?

Why drops and bubbles are spherical in shape?

Explain why ethylamine is stronger than ammonia ?

Explain why sportsmen use shoes with spikes.

(i) Draw a neat labelled ray diagram of a compound microscope. Explain briefly its working. (ii) Why must both the objective and the eye-piece of a compound microscope have short focal lengths ?

Explain why the following system is not aromatic?