Answer: Similar charges repel
Step-by-step explanation:
The group of students is conducting an experiment in order to see the effect of negative and positive charges.
They observed that similar charges repel each other. Example: When two negative charges were brought together then they repel each other.
When two positive charges were move towards each other then they repel each other.
This observation states that the similar charges repel each other whether it is positive-positive or negative-negative.