The handles of the tools like screwdrivers and pliers used by electrician for repair work usually have plastic or rubber covers on them. Can you explain why?

Lightning the thunder take place in the sky at the same time and at the same distance from us. Lightning is seen earlier and thunder is heard later. Can you explain why ?

Do you think an electromagnet can be used for separating plastic bags from a garbage heap? Explain.

We use colours dissolved in water during Holi and clothes gets spoiled. Many colours used to celebrate Holi are oxidized metals or industrial dyes mixed with engine oil. Doctors say these are harmful colours which should be banned for usage. Manufactures mix dyes with colours, and sell them for their profits. Holi lovers can make their Holi colourful by using natural colours available in the market.Natural colours start fading when they come in contact with sun rays. (i) Why doctors say that synthetic colours are harmful? (ii) What are natural colours? (iii) As a student what initiative you will take to motivate your classmates to use natural colours in Holi? Give any suggestions.