Answer:
The atoms that contain an unstable combination of neutrons and protons, or excess energy in their nucleus
My opinion, the answer is b
The answer is A. Polarized in a vertical plane
If positioned correctly, a polarized lenses can block all reflected light from horizontal surface such as road
The electrostatic force between two charges q1 and q2 is given by

where

is the Coulomb's constant and r is the distance between the two charges.
If we use F=19.2 N and q1=q2=-3.0 C, we can find the value of r, the distance between the two charges by re-arranging the previous formula: