Europium commonly forms Eu2+ Eu3+ in introductory ionic compounds.
| Element | Europium |
|---|---|
| Symbol | Eu |
| Atomic number | 63 |
| Common ionic charge | +2, +3 |
| Common ions | Eu2+, Eu3+ |
Images are used as visual references; charge rules still depend on the compound.
Europium is [Xe]4f7 6s2. Losing two electrons keeps the perfectly half-filled f7 shell, making Eu2+ the most stable divalent lanthanide by far; losing three gives conventional Eu3+ (f6). The two states sit close enough that phosphor chemists simply pick the host crystal that stabilizes the color they want.
This is a classroom reference range, not an exhaustive list of all oxidation states.
Assuming the lanthanide +3 rule has no real exceptions. Europium is the strongest one: Eu2+ is stable enough to survive in minerals, and geologists read 'europium anomalies' in rocks — Eu2+ substituting for Ca2+ in feldspar — as a fingerprint of how magmas evolved.
Eu2+ with SO4 2- gives EuSO4 — and like BaSO4 it is water-insoluble, because Eu2+ (117 pm) is nearly a twin of Ba2+ in size and charge. Charge and radius, not element identity, drive solubility patterns.
Europium chloride
Eu2+ balances chloride ions.
Europium oxide
Europium can form oxides where total positive and negative charge balances.
Under UV light, embedded Eu3+ complexes fluoresce red and Eu2+ phosphors add blue-green — a luminescent signature that is easy to verify and hard to counterfeit.
Usually Eu2+, doped into nitride or garnet hosts, converting blue LED light into the warm tones. Shift the host lattice and the same 2+ ion emits anywhere from blue to red.
The metal's electrons are arranged so it behaves almost like an alkaline-earth: it tarnishes in seconds and reacts with water like calcium — a preview of the 2+ character its ion is famous for.
Combine positive and negative ions so the total charge is zero — or let the ionic compound calculator do the crossing for you. The full chart lives on the periodic table with charges.
Charges and element facts on this page are checked against the primary references below. Found an error? Email hello@periodictablewithcharges.com — corrections ship in the next content update. See how this site is edited.