Chart of Nuclides
Physicists map the inventory of known nuclei on a "chart of nuclides."
On this chart, the horizontal axis represents the number of neutrons a nucleus contains
and the vertical axis shows the number of protons it possesses.
The region of stable nuclei is roughly found on a diagonal line,
where the neutron number approximately equals proton number.
Below this diagonal is a jagged line called the "neutron dripline" and above this diagonal is another jagged line called the "proton dripline."
Nuclei found above the proton dripline and below the neutron dripline tend to be highly
unstable and undergo radioactive decay readily. Also, there are certain "magic numbers"
for neutrons (vertical lines) and protons (horizontal lines) which help make a nucleus stable. (Courtesy Cary Davids, Argonne National
Laboratory.)
Link to Physics News Preview,Escape from a Nuclear Football
