Dubnium
Atomic number 105 means that every Dubnium nucleus contains 105 protons. That proton count is the element's identity: change it and you no longer have Dubnium.
Start with the nucleus
Atomic number 105 means that every Dubnium nucleus contains 105 protons. That proton count is the element's identity: change it and you no longer have Dubnium.
Dubnium (Db) is chemical element 105. It belongs to the transition metals, and its reference state at room temperature is not firmly established. Those basic facts are a useful starting point for its chemistry and applications.
In practice, it turns up most often in scientific research.
See the atom
Conceptual visual: electron shells are a learning aid, not a literal picture of quantum orbitals.
What this number means
Atomic number 105 means that every Dubnium nucleus contains 105 protons. That proton count is the element's identity: change it and you no longer have Dubnium.