Brief explanations of how to determine how many protons, neutrons, and electrons are in an element.

Entry explores the process of beta decay which occurs when, in a nucleus with too many protons or too many neutrons, one of the protons or neutrons is transformed into the other.

The Nobel Physics Chairman made this speech when presenting the Prize to Chadwick. It clearly explains the importance and depth of Chadwick's work. Site by Nobel e-Museum.

The Committee on Elementary-Particle Physics, part of the U.S. National Research Council, presents this massive report on particle physics. It's a definitive document. Surprisingly readable, totally detailed. Start with the Table of...