If you've never flown through one before. . .
Source: http://youtu.be/QATa1evuSec
A simple, often reproduced picture with what you need to know.
Protons and neutrons in the center, unmoving. Electrons in orbit around the nucleus at about 1/10th speed of light.
Positive protons, neutral neutrons, negative electrons.
Big protons and neutrons, little electrons.
The protons and neutrons occupy a small area. This zoom shows you how small it really is by comparing it to a marble on a baseball diamond. The outfield wall is the first electron path.
Although the nucleus is small, it is where most of the mass of the atom lies.
Much as the sun contains most of the mass (97%) of the solar systerm.
Disregard the section on quark color and gluon exchange. It is beyond the scope of most school education. It is interesting
