spread evenly throughout the model. located at multiple sites in the model. concentrated in the center of the model. positioned outside the center of the model.
I gave my students this multiple choice question: In the atomic model that includes a nucleus, the positive charge is

Only one answer is correct among these 4 choices:
- spread evenly throughout the model.
- located at multiple sites in the model.
- concentrated in the center of the model.
- positioned outside the center of the model.

Could you tell me which one is correct?

concentrated in the center of the model.