Answer:
B. An atom is a solid sphere
Explanation:
The idea that the atom was a solid sphere paved back to the first atomic model in the <em>19th century</em> theorized by <em>John Dalton</em>. According to him, an atom is <u>intact and hard and cannot be broken down or divided</u>.
However, many scientists continued to research and it was found that <em>the atom was not actually a solid sphere.</em> It was made up of<em> protons (positively-charged), electrons (negatively-charged) and neutrons (neutrally-charged). </em>This invalidated Dalton's solid sphere model.
Answer:
I'm not sure but I think it is convection.
