Question

7
a balloon that has been rubbed on wool has a negative charge. when the balloon is held over—but not touching—some bits of paper, some of the bits jump up to the balloon.
why does the paper move?
a. all balloons are magnets that can pull on plastic or paper without touching it.
b. a charged object can make other objects move without touching them.
c. a charged object can only push against other objects.

Explanation:

• Option A is incorrect because balloons are not magnets; the interaction here is electrostatic, not magnetic.
• Option B is correct. The balloon, after being rubbed (charged negatively), exerts an electrostatic force on the neutral paper bits, causing them to move without direct contact. This is due to electrostatic induction or the attraction between a charged object and a neutral conductor/insulator (paper, in this case).
• Option C is incorrect because a charged object can both attract (opposite charges) and repel (like charges); here, it's attracting the neutral paper (or inducing a charge separation in the paper to cause attraction).

Answer:

B. A charged object can make other objects move without touching them.