---
title: "Ytterbium (Yb) — element 70"
description: "Ytterbium is element 70, symbol Yb, atomic weight 173.05. Configuration, properties, uses and neighbours."
url: https://atoneplace.net/element/ytterbium/
site: "At One Place"
---

# Ytterbium (Yb)

**Ytterbium — element 70: Yb**

173.05 u · Lanthanide · period 6

Ytterbium optical lattice clocks are accurate to roughly one part in 10¹⁸, which means they would neither gain nor lose a second over the age of the universe, and they are precise enough to detect the gravitational time dilation from raising the clock by a centimetre. Ytterbium fibre lasers now dominate industrial metal cutting, having displaced CO₂ lasers for most sheet work. Its electrical resistance rises steeply under pressure, which was once exploited to instrument the ground near nuclear tests.

## Properties

- **Atomic number:** 70
- **Symbol:** Yb
- **Standard atomic weight:** 173.05 u
- **Category:** Lanthanide
- **Period:** 6
- **Block:** f-block
- **Electron configuration:** [Xe] 6s² 4f¹⁴
- **Electrons per shell:** 2, 8, 18, 32, 8, 2
- **Melting point:** 1,092 K — 818.9 °C — 1505.9 °F
- **Boiling point:** 1,469 K — 1195.8 °C — 2184.5 °F
- **Density:** 6.9 g/cm³
- **Oxidation states:** +3, +2
- **Discovered:** 1878 by Jean Charles Galissard de Marignac

## Electron configuration

- **Full:** 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴
- **Noble gas shorthand:** [Xe] 6s² 4f¹⁴
- **Shells:** K: 2 · L: 8 · M: 18 · N: 32 · O: 8 · P: 2

## What it is used for

- Ytterbium optical lattice clocks, the most accurate clocks ever built
- Ytterbium-doped fibre lasers for industrial cutting and welding
- Stress gauges, since its resistivity changes sharply with pressure
- Stainless steel grain refinement

> No Pauling electronegativity is listed in the standard tables for ytterbium.

## Neighbours in the table

| Z | Element | Symbol | Mass |
| --- | --- | --- | --- |
| 68 | Erbium | Er | 167.26 |
| 69 | Thulium | Tm | 168.93 |
| 70 | Ytterbium ← | Yb | 173.05 |
| 71 | Lutetium | Lu | 174.97 |
| 72 | Hafnium | Hf | 178.49 |

## Common questions

### What is the atomic number of ytterbium?

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

### What is the symbol for ytterbium?

Yb.

### What is the electron configuration of ytterbium?

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴, or [Xe] 6s² 4f¹⁴ in noble-gas shorthand.

### What is the melting point of ytterbium?

1,092 K — 818.9 °C — 1505.9 °F

## Related pages

- [Erbium (Er)](https://atoneplace.net/element/erbium/)
- [Thulium (Tm)](https://atoneplace.net/element/thulium/)
- [Lutetium (Lu)](https://atoneplace.net/element/lutetium/)
- [Hafnium (Hf)](https://atoneplace.net/element/hafnium/)

## Sources

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