What Is Europium?

Europium, atomic number 63 and symbol Eu, belongs to the lanthanides — the row of rare earth elements beneath the main periodic table.

The softest and most reactive lanthanide. Used as red phosphor in TV and computer screens.

As a lanthanide in Period 6 and Group 3 (Transition Metals), europium's placement on the table reflects its electron configuration of [Xe] 4f⁷ 6s², which governs its bonding behavior and the type of compounds it typically forms.

Position on the Periodic Table

Europium is located in Period 6, an unusually long row that includes the entire lanthanide series.

Within that row, europium sits in Group 3 (Transition Metals), alongside elements that share a similar number of valence electrons and, by extension, similar chemical behavior.

This position is not arbitrary — the periodic table was deliberately organized so that an element's row and column reveal its expected reactivity, bonding pattern, and physical state at a glance.

Physical & Chemical Properties

Europium has an atomic mass of 151.964 u and a density of 5.243 g/cm³. Its melting point is 822°C and its boiling point is 1527°C.

Europium displays the typical lanthanide combination of a silvery appearance and chemistry dominated by its f-orbital electrons.

Electron Configuration Explained

Europium's electron configuration is [Xe] 4f⁷ 6s², describing how its electrons are distributed across shells and subshells around the nucleus.

Reading the configuration in order shows electrons filling shells of increasing energy, following the standard Aufbau principle that explains how atomic structure builds up across the periodic table.

The outermost (valence) electrons shown in this configuration are what ultimately determine europium's chemical reactivity and the type of bonds it forms with other elements.

History & Discovery

Europium was formally discovered in 1901, E. Demarçay, identified through the careful isolation and analytical techniques typical of that era's chemical research.

Many elements from this period were anticipated by Dmitri Mendeleev's periodic table, which successfully predicted gaps corresponding to undiscovered elements well before laboratory instruments existed to confirm them directly.

What Is Europium Used For?

Europium's specific properties make it useful in several applications, including:

  • Red phosphors (TVs/LEDs)
  • Euro banknote security
  • Fluorescent lamps
  • Lasers
  • Nuclear research

These uses reflect europium's underlying classification as a lanthanide, since the same properties that define its category in chemistry also determine where it becomes practically useful.

Fun Facts About Europium

  • Europium phosphors glow under UV on euro banknotes as a security feature.
  • Europium is element number 63 on the periodic table, in Period 6 and Group 3.
  • Its standard atomic mass is 151.964 u, calculated from the natural abundance of its isotopes.

Frequently Asked Questions

What is Europium's atomic number?
Europium has atomic number 63.

What is Europium's chemical symbol?
Europium's symbol is Eu.

What group and period is Europium in?
Europium is in Period 6, Group 3 (Transition Metals).

What is Europium's atomic mass?
Europium's standard atomic mass is 151.964 u.