Strontium
Atomic number 38 means that every Strontium nucleus contains 38 protons. That proton count is the element's identity: change it and you no longer have Strontium.
Start with the nucleus
Atomic number 38 means that every Strontium nucleus contains 38 protons. That proton count is the element's identity: change it and you no longer have Strontium.
Strontium (Sr) is chemical element 38. It belongs to the alkaline-earth 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 fireworks, magnets and medical applications.
See the atom
Conceptual visual: electron shells are a learning aid, not a literal picture of quantum orbitals.
What this number means
Atomic number 38 means that every Strontium nucleus contains 38 protons. That proton count is the element's identity: change it and you no longer have Strontium.