Nickel (Ni) is the element with atomic number 28, symbol Ni. It has five stable isotopes.
It is thought be the product of supernova nucleosynthesis. Nickel-58 is the most common isotope; several nucleosynthesis paths lead to it. Nickel-56 is in the alpha ladder, is unstable, and leading to the stable isotope iron-56 through two beta decays. Nickel-62 is very stable, having the highest binding energy of any nucleus (more than iron-56), and is not abundant because nucleosynthesis paths to it have low-probability steps.