Question

When negative object placed in front of neutral object will it move?

Answer 1

The negatively charged body induces postive charge on the nearer side and negative on the farther side.
 If the farther side is earthed it doesnt lose all its electrons but some of them.
The number of electrons lost corresponds to charge induced on the body.

If Q is the charge induced
Q = ne
Implies n = Q/e where n is number of electrons lost.
e is charge of electron which is -1.6 × 10^-19 C