Compute each part of given problem:
Problem: A small piece of dust of mass m = 1.3 mu or micro g travels horizontally through an electric air cleaner in which the electric field is 479 N/C. The electric force on the particle is equal to the weight of the particle.
Part A: What is the charge on the dust particle?
Part B: If this charge is provided by an excess of electrons, how many electrons does that correspond to?
Express your knowledge to solve the above problem.