The statement that electric charge is an integral multiple of the electronic charge $e$ was experimentally proven by whom?

The net electric charge of a conductor does not change when:

Write the unit and value of the fundamental electric charge.

When a piece of polythene is rubbed with wool,a negative charge of $4 \times 10^{-7} \ C$ is developed on the polythene. The number of electrons transferred from wool to polythene is $\left[e = 1.6 \times 10^{-19} \ C\right]$.

Which of the following is not true about electric charge?

The electric charge on an $\alpha$-particle is ....... .