Negative charges repel positive charges. t/f if a negatively charged rod is brought close to an electroscope that is negatively charged, the two leaves will move farther apart. t/f electrical charges exist in the sea and in the air. t/f coulomb's law describes gravitational attraction t/f an insulator does not allow electrons to flow freely through it. t/f coulomb's law predicts that charged bodies may attract or repel each other. t/f electric fields have magnitude and direction. t/f an electric field is a measure of the force on a unit positive charge. t/f