Nickel
Atomic number 28 means that every Nickel nucleus contains 28 protons. That proton count is the element's identity: change it and you no longer have Nickel.
Start with the nucleus
Atomic number 28 means that every Nickel nucleus contains 28 protons. That proton count is the element's identity: change it and you no longer have Nickel.
Nickel (Ni) is chemical element 28. It belongs to the transition metals, and its reference state at room temperature is a solid. Those basic facts are a useful starting point for its chemistry and applications.
In practice, it turns up most often in stainless steel, batteries and coins and monetary alloys.
See the atom
Conceptual visual: electron shells are a learning aid, not a literal picture of quantum orbitals.
What this number means
Atomic number 28 means that every Nickel nucleus contains 28 protons. That proton count is the element's identity: change it and you no longer have Nickel.