Multiple choice What process causes the ground to become positively charged during a thunderstorm? induction by the negatively-charged cloud induction by the positively-charged cloud contact with lightning negatively-charged raindrops Reveal answer Fill a bubble to check yourself A Correct answer Explanation The negative charges at the base of a storm cloud repel electrons in the ground, pushing them deeper and leaving the surface with a net positive charge. This process is known as electrostatic induction.