Manganese
Atomic number 25 means that every Manganese nucleus contains 25 protons. That proton count is the element's identity: change it and you no longer have Manganese.
Start with the nucleus
Atomic number 25 means that every Manganese nucleus contains 25 protons. That proton count is the element's identity: change it and you no longer have Manganese.
Manganese (Mn) is chemical element 25. 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 metallurgy and steel, batteries and biology.
See the atom
Conceptual visual: electron shells are a learning aid, not a literal picture of quantum orbitals.
What this number means
Atomic number 25 means that every Manganese nucleus contains 25 protons. That proton count is the element's identity: change it and you no longer have Manganese.