a lightweight core surrounded by neutral particles a massive core surrounded by negatively-charged particles a network of interacting positive and negative particles overlapping layers of neutral, positive, and negative particles
I gave my students this multiple choice question: Which best describes the structure of an atom?

Only one answer is correct among these 4 choices:
- a lightweight core surrounded by neutral particles
- a massive core surrounded by negatively-charged particles
- a network of interacting positive and negative particles
- overlapping layers of neutral, positive, and negative particles

Could you tell me which one is correct?

a massive core surrounded by negatively-charged particles