Nickel (Ni): Nickel is a hard, metallic element that found in igneous rocks. Without nickel, stainless steel would be less resistant to heat and corrosion. Atomic number 28, atomic weight 58.71.

It is the number of protons in an atom’s nucleus, known as its atomic number, that determines which element it represents. If you have one proton, that is hydrogen. If you have 12 protons ...