A student investigates how charge is distributed in a conductor. She tapes two unopened cans of soda onto foam cups as shown below. The cans are touching each other. She places a negatively charged balloon near the can on the left as shown.

Question

In which direction do the negatively charged atoms inside the soda cans move?

From the bottom to the top of the cans
From the top to the bottom of the cans
From the left to the right of the cans
From the right to the left of the cans

Answer 1

When a negatively charged balloon is brought near the left can, it creates an electric field that affects the distribution of charge within the two cans. Since the cans are conductors, the negatively charged balloon will induce a separation of charges within the conductive material of the cans.

As the negatively charged balloon approaches the left can, the negative charges (electrons) in that can are repelled away from the side facing the balloon and will move toward the opposite side of the can. Since the two cans are touching, this will also affect the charges in the right can. The negative charges in the left can move toward the right can.

Thus, the movement of the negatively charged atoms (electrons) inside the soda cans will be:

From the left to the right of the cans.