Mendeleev
Periodic table · chemistry · physics
Element story

Promethium

Atomic number 61 means that every Promethium nucleus contains 61 protons. That proton count is the element's identity: change it and you no longer have Promethium.

Start with the nucleus

Atomic number 61 means that every Promethium nucleus contains 61 protons. That proton count is the element's identity: change it and you no longer have Promethium.

Promethium (Pm) is chemical element 61. 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 nuclear batteries, scientific research and luminous paint.

See the atom

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

What this number means

Atomic number 61 means that every Promethium nucleus contains 61 protons. That proton count is the element's identity: change it and you no longer have Promethium.

Keep exploring

→ Promethium · Atomic structure · Periodic trends

61PmPromethium
Promethium · Pm · Z = 61

Promethium (Pm) is chemical element 61. 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

Promethium (Pm) is chemical element 61. 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 nuclear batteries, scientific research and luminous paint.

What its position in the table tells us

Promethium 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.