What is the difference between contact and action-at-a-distance forces?
A. Action-at-a-distance forces are stronger than contact forces.
B. Contact forces are stronger than action-at-a-distance forces.
C. Contact forces require objects to physically touch, while action-at-a-distance forces do not.
D Action-at-a-distance forces require objects to physically touch, while contact forces do not.

A

Contact forces are forces that require the actual contact (touching) of two pieces of matter. ... A field force is a force that works at a distance. No touching is required. Gravity is a good example of a field force, because it works whether or not an object is touching something or touching nothing at all.

what experimental evidence led scientists to change from the previous model to this one?

a few of the positive particles aimed at a gold foil seemed to bounce back.

the colors of light emitted from heated atoms had very specific energies.

experiments with water vapor showed that elements combine in specific proportions.

cathode rays were bent in the same way whenever a magnet was brought near them.