The fact that electric charges are integral multiples of the fundamental electronic charge was proved experimentally by

Which scientist represented the types of charges?

Which of the following charges is possible?
$(a)\ 3.2 \times 10^{-20} C$ $(b)\ 3.2 \times 10^{-18} C$
$(c)\ 3 \times 10^{-19} C$ $(d)\ 6 \times 10^{-17} C$

$A$ $1$ paisa coin is made up of an $Al-Mg$ alloy and weighs $0.75\, g$. It has a square shape and its diagonal measures $17\, mm$. It is electrically neutral and contains equal amounts of positive and negative charges. Calculate the total amount of positive or negative charge in the coin.

When ${10^{19}}$ electrons are removed from a neutral metal plate,the electric charge on it is

What is the meaning of the additive nature of electric charges?