Question

A student is investigating what happens when a neutral metal sphere sitting on an insulated stand is touched by a negatively charged rod. The set up for the student's investigation is shown in the diagram.

image 3845826dd9f243109fa16213cd34e0d4

What will happen to the excess electrons when the negatively charged rod touches the metal sphere?

A.
The excess electrons will move from the sphere to the rod and spread out along the rod.

B.
The excess electrons will move from the rod to the sphere and spread out on the sphere.

C.
The excess electrons will move from the rod to the sphere and stay clustered in the area where the rod touches the sphere.

D.
The excess electrons will move from the sphere to the rod and stay clustered near the end of the rod that touches the sphere.

Answer 1

When a negatively charged rod touches a neutral metal sphere, the excess electrons from the rod will move toward the neutral sphere. The reason for this is that the neutral sphere initially has an equal number of positive and negative charges. However, when the negatively charged rod comes into contact with it, it will influence the distribution of charges.

The movement of electrons will cause the neutral sphere to gain negative charge as the electrons from the rod move onto the sphere. Because the sphere is a conductor, the electrons that move onto it will spread out evenly over the surface of the sphere.

Given the options provided, the correct answer is:

**B. The excess electrons will move from the rod to the sphere and spread out on the sphere.**