Question

why does a balloon that has been rubbed stick to a wall for a while?
multiple choice
both the balloon and the wall are insulators, which attracts the balloon.
friction transfers electrons to the balloon, which repels electrons in the wall, giving it a positive charge and opposite charges attract.
a balloon is made of rubber, an insulator, which stops static electricity.
rubbing always creates an attractive force.

Explanation:

When a balloon is rubbed, friction transfers electrons to it (charging by friction). When brought near a wall, the negatively - charged balloon repels electrons in the wall (which is a conductor, but the key is the charge separation). This leaves a region of positive charge in the wall near the balloon. Opposite charges (negative on balloon and positive on the wall) attract each other.

• Option 1: Just being insulators is not the reason for the attraction. Insulators can be charged, but the key is the charge interaction (opposite charges attract), not just the property of being an insulator.
• Option 2: Friction transfers electrons to the balloon (charging it negatively). It repels electrons in the wall (if the wall is a conductor, electrons move away, leaving a positive charge near the balloon; if it's an insulator, there is a polarization). Opposite charges attract. This is in line with the principle of static electricity (charge - induced charge separation and attraction).
• Option 3: A balloon being made of rubber (an insulator) is not the direct reason for sticking. Insulators can hold charge (due to friction), but the attraction is due to charge interaction (opposite charges), not just the material being an insulator.
• Option 4: Rubbing does not always create an attractive force. For example, if two objects of the same material are rubbed (assuming similar electron - affinity), there may be no significant charge transfer, and no attractive force. The attraction is due to charge separation and opposite - charge interaction.

Answer:

B. Friction transfers electrons to the balloon, which repels electrons in the wall, giving it a positive charge and opposite charges attract.