Mendeleev
Periodic table · chemistry · physics
Element story

Terbium

Atomic number 65 means that every Terbium nucleus contains 65 protons. That proton count is the element's identity: change it and you no longer have Terbium.

Start with the nucleus

Atomic number 65 means that every Terbium nucleus contains 65 protons. That proton count is the element's identity: change it and you no longer have Terbium.

Terbium (Tb) is chemical element 65. 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 phosphors, magnets and fuel-cell materials.

See the atom

Conceptual visual: electron shells are a learning aid, not a literal picture of quantum orbitals.

What this number means

Atomic number 65 means that every Terbium nucleus contains 65 protons. That proton count is the element's identity: change it and you no longer have Terbium.

Keep exploring

→ Terbium · Atomic structure · Periodic trends

65TbTerbium
Terbium · Tb · Z = 65

Terbium (Tb) is chemical element 65. 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

Terbium (Tb) is chemical element 65. 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 phosphors, magnets and fuel-cell materials.

What its position in the table tells us

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