A scientist wipes a rubber rod with a wool cloth which leads to a negative charge on the rod. After this, the scientist touches the rod to a neutral metal sphere. This will transfer the negative charges from the rod to the sphere:

Question

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Which statement explains what will happen to the negative charge, and why?

(1 point)
Responses

It will remain only on one spot of the sphere, because the low conductivity of the metal prevents the charges from spreading out.
It will remain only on one spot of the sphere, because the low conductivity of the metal prevents the charges from spreading out.

It will slowly move to the bottom of the sphere, because the charges are heavy and will sink to the bottom.
It will slowly move to the bottom of the sphere, because the charges are heavy and will sink to the bottom.

It will only spread to the air around the sphere, because negative charges need to occupy a big area.
It will only spread to the air around the sphere, because negative charges need to occupy a big area.

It will spread uniformly over the surface of the sphere, because of the conducting nature of the sphere and similar charges push away from each other.

Answer 1

The correct statement is:

It will spread uniformly over the surface of the sphere, because of the conducting nature of the sphere and similar charges push away from each other.

This is true because when a charged object (in this case, the rubber rod) comes into contact with a conducting object (the metal sphere), the free electrons in the conductor will redistribute themselves in response to the negative charges from the rod. The like charges repel each other, causing the negative charges to spread out evenly over the surface of the conducting sphere until electrostatic equilibrium is reached.