A0.13 g plastic bead is charged by the addition of 1.0ã1010 excess electrons. what electric field eâ (strength) will cause the bead to hang suspended in the air?

The working equation for this is: E = F/Q, where E is the strength of electric field, F is the force and Q is the charge. The force is equal to:

F = mg = (0.13/1000 kg)(9.81 m/s²) = 1.2753×10⁻³ N

The charge of he excess electrons is equal to:
Q = (-1.6021766208×10⁻¹⁹ C/electron)(1×10¹⁰ electrons)
Q = -1.6021766208×10⁻⁹ C

E = 1.2753×10⁻³ N/-1.6021766208×10⁻⁹ C
E = -795,979.66 N/C