Question

two objects are held close together. when they are released, they move toward one another. which conclusion is supported by this evidence?
the objects are both positively charged.
the objects are both negatively charged.
the objects have no charge.
the objects have opposite charges.

Explanation:

To solve this, we recall the principles of electric charges: like charges (both positive or both negative) repel each other, and opposite charges attract. If two objects move toward each other when released, they must be attracting, which happens when they have opposite charges. Objects with no charge would not exert a force to move toward each other (unless due to other forces, but in the context of charge interactions, neutral objects don't attract each other in this way). So the correct conclusion is that the objects have opposite charges.

Answer:

The objects have opposite charges.