Mendeleev
Periodic table · chemistry · physics
Element story

Lutetium

Atomic number 71 means that every Lutetium nucleus contains 71 protons. That proton count is the element's identity: change it and you no longer have Lutetium.

Start with the nucleus

Atomic number 71 means that every Lutetium nucleus contains 71 protons. That proton count is the element's identity: change it and you no longer have Lutetium.

Lutetium (Lu) is chemical element 71. It belongs to the lanthanoids, 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 catalysts, medical imaging equipment and 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 71 means that every Lutetium nucleus contains 71 protons. That proton count is the element's identity: change it and you no longer have Lutetium.

Keep exploring

→ Lutetium · Atomic structure · Periodic trends

71LuLutetium
Lutetium · Lu · Z = 71

Lutetium (Lu) is chemical element 71. It belongs to the lanthanoids, and its reference state at room temperature is a solid. Those basic facts are a useful starting point for its chemistry and applications.

Understanding the element

Lutetium (Lu) is chemical element 71. It belongs to the lanthanoids, and its reference state at room temperature is a solid. Those basic facts are a useful starting point for its chemistry and applications.

Where do we encounter it?

In practice, it turns up most often in catalysts, medical imaging equipment and scientific research.

What its position in the table tells us

Lutetium sits in period 6, group 3 and the D block. That location is useful because neighbouring elements often share trends in valence electrons, oxidation states and bonding behaviour.