What is electric charge ? Is it scalar or vector ?

$(a)$ A comb run through one’s dry hair attracts small bits of paper. Why?

    What happens if the hair is wet or if it is a rainy day? (Remember, a paper does not conduct electricity.)

$(b)$ Ordinary rubber is an insulator. But special rubber tyres of aircraft are made slightly conducting. Why is this necessary?

$(c)$ Vehicles carrying inflammable materials usually have metallic ropes touching the ground during motion. Why?

$(d)$ A bird perches on a bare high power line, and nothing happens to the bird. A man standing on the ground touches the same line and gets a fatal shock. Why?

Is the induced charge on the surface of metal or inside it ?

The minimum charge on an object is

A polythene piece rubbed with wool is found to have a negative charge of $3 \times 10^{-7} \;C$

$(a)$ Estimate the number of electrons transferred (from which to which?)

$(b)$ Is there a transfer of mass from wool to polythene?