---
title: "Europium (Eu) — element 63"
description: "Europium is element 63, symbol Eu, atomic weight 151.96. Configuration, properties, uses and neighbours."
url: https://atoneplace.net/element/europium/
site: "At One Place"
---

# Europium (Eu)

**Europium — element 63: Eu**

151.96 u · Lanthanide · period 6

Europium gave colour television a usable red: before europium-doped phosphors arrived in the 1960s, the red channel was so dim that the whole picture had to be run darker to match it. The euro banknote carries europium compounds that glow specific colours under ultraviolet, which is one of the checks a cash machine makes. It is the softest and least dense lanthanide, and the most reactive — a fresh surface tarnishes in seconds and the metal has to be kept under oil.

## Properties

- **Atomic number:** 63
- **Symbol:** Eu
- **Standard atomic weight:** 151.96 u
- **Category:** Lanthanide
- **Period:** 6
- **Block:** f-block
- **Electron configuration:** [Xe] 6s² 4f⁷
- **Electrons per shell:** 2, 8, 18, 25, 8, 2
- **Melting point:** 1,095 K — 821.9 °C — 1511.3 °F
- **Boiling point:** 1,802 K — 1528.8 °C — 2783.9 °F
- **Density:** 5.24 g/cm³
- **Oxidation states:** +3, +2
- **Discovered:** 1901 by Eugène-Anatole Demarçay

## Electron configuration

- **Full:** 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f⁷
- **Noble gas shorthand:** [Xe] 6s² 4f⁷
- **Shells:** K: 2 · L: 8 · M: 18 · N: 25 · O: 8 · P: 2

## What it is used for

- The red phosphor in colour televisions, LED lamps and fluorescent tubes
- Anti-counterfeiting marks in euro banknotes
- Neutron absorbers in reactor control rods
- Blue-emitting phosphors in white LEDs

> No Pauling electronegativity is listed in the standard tables for europium; scales that estimate one put it near 1.2.

## Neighbours in the table

| Z | Element | Symbol | Mass |
| --- | --- | --- | --- |
| 61 | Promethium | Pm | [145] |
| 62 | Samarium | Sm | 150.36 |
| 63 | Europium ← | Eu | 151.96 |
| 64 | Gadolinium | Gd | 157.25 |
| 65 | Terbium | Tb | 158.93 |

## Common questions

### What is the atomic number of europium?

63. That is the number of protons in its nucleus, which is what defines the element.

### What is the symbol for europium?

Eu.

### What is the electron configuration of europium?

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f⁷, or [Xe] 6s² 4f⁷ in noble-gas shorthand.

### What is the melting point of europium?

1,095 K — 821.9 °C — 1511.3 °F

## Related pages

- [Promethium (Pm)](https://atoneplace.net/element/promethium/)
- [Samarium (Sm)](https://atoneplace.net/element/samarium/)
- [Gadolinium (Gd)](https://atoneplace.net/element/gadolinium/)
- [Terbium (Tb)](https://atoneplace.net/element/terbium/)

## Sources

- Official vendor product documentation — At One Place (/about/)