What led scientists to conclude that most of the atom's mass is for concentrated in a very small nucleus? What particles are responsible that mass?

1 Answer
Oct 29, 2016

What else but experiment?

Explanation:

The massive particles are the nuclear protons, and neutrons. See this [old answer.](https://socratic.org/questions/why-did-ruther-ford-s-only-choose-the-gold-foil-for-experiment)