is an isotope
with 28 protons
and 34 neutrons
. It is a stable isotope
, and in fact has the highest nuclear binding energy
of any known isotope (8.7946 Mev/nucleon). This makes it an "end product" of many nuclear reactions throughout the universe and accounts for the high relative abundance of nickel. However if one looks only at the nuclei proper (without including the electron cloud), it has the third lowest mass per baryon (930.186 MeV) after Fe-56 (930.174 MeV) and Ni-60 (930.180 MeV), and just above Cr-52 (930.192 MeV) and Fe-58 (930.193 MeV).