---
title: "Hassium (Hs) — element 108"
description: "Hassium is element 108, symbol Hs, most stable isotope 269. Configuration, properties, uses and neighbours."
url: https://atoneplace.net/element/hassium/
site: "At One Place"
---

# Hassium (Hs)

**Hassium — element 108: Hs**

[269] · Transition metal · period 7, group 8

Hassium is the heaviest element whose chemistry has been studied in any depth. In 2001 a team made a handful of atoms, let them react with oxygen, and showed the product deposited on a cold surface just as osmium tetroxide does — hassium tetroxide exists, and hassium is a group 8 metal. If anything ever gets weighed at this end of the table it will probably be hassium: theory suggests it may be the densest element of all, around 41 g/cm³, roughly twice osmium, though no one has ever measured it and no one is likely to.

## Properties

- **Atomic number:** 108
- **Symbol:** Hs
- **Mass number of most stable isotope:** [269]
- **Category:** Transition metal
- **Group:** 8
- **Period:** 7
- **Block:** d-block
- **Electron configuration:** [Rn] 7s² 5f¹⁴ 6d⁶
- **Electrons per shell:** 2, 8, 18, 32, 32, 14, 2
- **Oxidation states:** +8, +6, +5, +4, +3, +2
- **Discovered:** 1984 by Peter Armbruster, Gottfried Münzenberg and colleagues at GSI Darmstadt

## Electron configuration

- **Full:** 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 7s² 5f¹⁴ 6d⁶
- **Noble gas shorthand:** [Rn] 7s² 5f¹⁴ 6d⁶
- **Shells:** K: 2 · L: 8 · M: 18 · N: 32 · O: 32 · P: 14 · Q: 2

## What it is used for

- Research only; no application outside the laboratory

## Hazards

- Intensely radioactive; exists only as individual atoms in an accelerator

> Melting point, boiling point, density and electronegativity are omitted. The often-quoted density of 41 g/cm³ is a calculation from the predicted crystal structure, not a measurement, which is exactly why it is not in the density field. The mass given is the mass number of hassium-269, the longest-lived confirmed at roughly 16 seconds; some longer-lived isotopes have been reported and not yet confirmed. Named after Hassia, the Latin name for the German state of Hesse.

> Several physical properties are not listed for hassium because no bulk sample has ever existed. Only a handful of atoms have been produced, often with half-lives measured in seconds, so published melting points and densities for elements in this range are calculations rather than measurements. They are omitted rather than presented as observed values.

## Neighbours in the table

| Z | Element | Symbol | Mass |
| --- | --- | --- | --- |
| 106 | Seaborgium | Sg | [269] |
| 107 | Bohrium | Bh | [270] |
| 108 | Hassium ← | Hs | [269] |
| 109 | Meitnerium | Mt | [278] |
| 110 | Darmstadtium | Ds | [281] |

## Group 8

Elements in the same group share their outer electron count, which is why they behave similarly in reactions. Hassium sits in group 8 with iron, ruthenium, osmium.

## Common questions

### What is the atomic number of hassium?

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

### What is the symbol for hassium?

Hs.

### What is the electron configuration of hassium?

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 7s² 5f¹⁴ 6d⁶, or [Rn] 7s² 5f¹⁴ 6d⁶ in noble-gas shorthand.

## Related pages

- [Seaborgium (Sg)](https://atoneplace.net/element/seaborgium/)
- [Bohrium (Bh)](https://atoneplace.net/element/bohrium/)
- [Meitnerium (Mt)](https://atoneplace.net/element/meitnerium/)
- [Darmstadtium (Ds)](https://atoneplace.net/element/darmstadtium/)
- [Iron (Fe)](https://atoneplace.net/element/iron/)
- [Ruthenium (Ru)](https://atoneplace.net/element/ruthenium/)
- [Osmium (Os)](https://atoneplace.net/element/osmium/)

## Sources

- Typical range compiled from manufacturer specifications — At One Place (/about/)