108
Hs
Hassium
277

Hassium (Hs)

Transition MetalGroup 8Period 7d-block-blockRadioactive

Hassium is a chemical element with symbol Hs and atomic number 108, named after the German state of Hesse. It is a synthetic element (an element that can be created in a laboratory but is not found in nature) and radioactive; the most stable known isotope, 269Hs, has a half-life of approximately 9.7 seconds, although an unconfirmed metastable state, 277mHs, may have a longer half-life of about 130 seconds. More than 100 atoms of hassium have been synthesized to date.

Latin name: Hassium

Atomic Number
108
Atomic Mass
277 g/mol
Phase (STP)
Solid (predicted)
Electron Config.
[Rn] 5f¹⁴ 6d⁶ 7s²

General

SymbolHs
Atomic Number108
Atomic Mass277 g/mol
CategoryTransition Metal
Group8
Period7
Blockd-block
Electron Configuration[Rn] 5f¹⁴ 6d⁶ 7s²
Valence Electrons8
Colourmetallic (predicted)

Physical Properties

Phase (STP)Solid (predicted)
Density41 (predicted)
Melting Point1260 (predicted)
Boiling PointUnknown

Atomic Properties

Atomic Radius237 pm
Electronegativity1.3 Pauling
Oxidation States+8
Ion ChargeHs8+

Nuclear & Hazards

RadioactiveYes
Half-life11 minutes (Hs-277)

Abundance

In Earth's Crust0%

Discovery & History

Discovery Year1984
Discovered ByGesellschaft für Schwerionenforschung (GSI), Darmstadt
Country of DiscoveryGermany

Isotopes of Hassium

IsotopeAbundanceHalf-lifeDecay
Hs-269~9.7 secondsα
Hs-277~11 minutesα

External References

← 107 Bohrium109 Meitnerium →