neutrons

phet.colorado.edu

How does changing the number of neutrons or protons affect the nuclear species, the stability of a nucleus, and its possible decay mechanisms? Explore different species, and learn about the common decay paths! Visualize these through the chart of the nuclides and discover the inner energy levels of the nucleus.

phet.colorado.edu

Build an atom out of protons, neutrons, and electrons, and see how the element, charge, and mass change. Then play a game to test your ideas!