Question

a balloon is rubbed with a piece of cloth. as a result, the balloon has a negative charge. what has happened?

• electrons have moved from the inside to the outside of the balloon.
• positive charges have traveled from the balloon to the cloth.
• electrons have moved from the balloon to the cloth.
• electrons have traveled from the cloth to the balloon.

Explanation:

When an object becomes negatively charged, it gains electrons (since electrons are negatively charged). When the balloon is rubbed with cloth, electrons from the cloth move to the balloon, giving the balloon a negative charge. Let's analyze each option:

• "Electrons have moved from the inside to the outside of the balloon": This doesn't explain the balloon getting a negative charge from rubbing with cloth. Eliminate.
• "Positive charges have traveled from the balloon to the cloth": Positive charges (protons) are not mobile in this context; only electrons move. Eliminate.
• "Electrons have moved from the balloon to the cloth": This would make the balloon lose electrons and become positive, not negative. Eliminate.
• "Electrons have traveled from the cloth to the balloon": This means the balloon gains electrons, becoming negatively charged, which matches the scenario.

Answer:

D. Electrons have traveled from the cloth to the balloon.