http://upload.wikimedia.org/math/5/5/7/557cb46ae9126680a7d579dd5e15015a.png http://upload.wikimedia.org/math/5/5/7/557cb46ae9126680a7d57... Basically one of th

http://upload.wikimedia.org/math/5/5/7/557cb46ae9126680a7d579dd5e15015a.png http://upload.wikimedia.org/math/5/5/7/557cb46ae9126680a7d57... Basically one of the neutrons kicks out a beta particle and becomes a proton. The atomic number goes up but the mass number stays the same.