Bromine
Atomic number 35 means that every Bromine nucleus contains 35 protons. That proton count is the element's identity: change it and you no longer have Bromine.
Start with the nucleus
Atomic number 35 means that every Bromine nucleus contains 35 protons. That proton count is the element's identity: change it and you no longer have Bromine.
Bromine (Br) is chemical element 35. It belongs to the halogens, and its reference state at room temperature is a liquid. Those basic facts are a useful starting point for its chemistry and applications.
In practice, it turns up most often in flame retardants, photography and chemical synthesis.
See the atom
Conceptual visual: electron shells are a learning aid, not a literal picture of quantum orbitals.
What this number means
Atomic number 35 means that every Bromine nucleus contains 35 protons. That proton count is the element's identity: change it and you no longer have Bromine.