108
  Hs  
269.000000
Hassium

Name: Hassium
Symbol: Hs
Atomic Number: 108
AtomicWeight: 269.000000
Family: Transition Metals
CAS RN: 54037-57-9
Description: A synthetic element not present in nature, appearance unknown, probably metallic solid.
State (25C): Unknown (Synthetic)
Oxidation states: unknown

Molar Volume: unknown
Valence Electrons: 6d67s2

Boiling Point:  unknown
Melting Point:
unknown
Electrons Energy Level: 2, 8, 18, 32, 32, 14, 2
Isotopes: 15 + None Stable
Heat of Vaporization: unknown
Heat of Fusion: unknown
Density: unknown
Specific Heat: unknown
Atomic Radius: unknown
Ionic Radius: unknown
Electronegativity: unknown
Vapor Pressure: unknown
1s2 2s2p6 3s2p6d10 4s2p6d10f14 5s2p6d10f14 6s2p6d6 7s2

History

Hassium was first synthesized in 1984 by a German research team led by Peter Armbruster and Gottfried Munzenberg at the Institute for Heavy Ion Research (Gesellschaft fr Schwerionenforschung) in Darmstadt.  Some controversy appears to exist regarding the process of identifying Element 108.

The first suggests:

The reaction producing the element was proposed and applied earlier by a Dubna Group led by Oganessian in 1976.  A target of 209Bi was bombarded by a beam of 54Cr ions.  In 1984 experiments at Dubna using the 157-inch cyclotron, produced 262107 by the reaction 209Bi + 54Cr.  The alpha decay of 246Cf, the sixth member in the decay chain of 262107, served to establish a 1-neutron reaction channel.

The second suggests:

They bombarded atoms of 108Pb with ions of 58Fe with a device known as a linear accelerator.  This produced atoms of hassium-265, an isotope with a half-life of about 2 milliseconds (0.002 seconds), and a free neutron.

The name hassium was proposed by Peter Armbruster and Gottfried Munzenberg, derived from the Latin name for the German state of Hessen where the institute is located.

There was an element naming controversy as to what the elements from 101 to 109 were to be called; thus IUPAC adopted unniloctium symbol Uno) as a temporary element name for this element.  In 1994 a committee of IUPAC recommended that element 108 be named hahnium.  The name hassium was adopted internationally in 1997.

1s2
2s2 2p6
3s2 3p6 3d10
4s2 4p6 4d10 4f14
5s2 5p6 5d10 5f14
6s2 6p6 6d6
7s2

Isotopes

Hassium's most stable isotope,  hassium-277, has a half-life of about 40 minutes.   It decays into seaborgium-273 through alpha decay or decays through spontaneous fission.

atom.gif (700 bytes)

Isotope  
Atomic Mass
 
Half-Life
263Hs 263.12856 ~1 ms
264Hs 264.12839 540 s
265Hs 265.13009 2.1 ms
266Hs 266.13010 2.7 ms
267Hs 267.13179 32 ms
268Hs 268.13216 ~2 seconds
269Hs 269.13406 27 seconds
270Hs 270.13465 3.6 seconds
271Hs 271.13766 ~40 seconds
272Hs 272.13905 ~40 seconds
273Hs 273.14199 ~50 seconds
274Hs 274.14313 ~1 minutes
275Hs 275.14595 0.15 seconds
276Hs 276.14721 ~1 hours
277Hs 277.14984 40 minutes

Hassium-270

Isotope-270 of Hassium, discovered by an international team of scientists led by the Technical University of Munich in December 2006, is a doubly magic isotope with an unusually long half-life of 22 seconds.  The existence of such relatively stable heavy isotopes had already been theoretically predicted, with some theories suggesting Hassium-270 may form part of an island of stability.

atom.gif (700 bytes)

Hassium Data
 

Atomic Structure

  • Atomic Radius:
  • Atomic Volume:
  • Covalent Radius:
  • Cross Section (Thermal Neutron Capture) Barns: 
  • Crystal Structure:
  • Electron Configuration:
    1s2 2s2p6 3s2p6d10 4s2p6d10f14 5s2p6d10f14 6s2p6d6 7s2
  • Electrons per Energy Level: 2, 8, 18, 32, 32, 14, 2
  • Ionic Radius:
  • Filling Orbital:
  • Number of Electrons (with no charge): 108
  • Number of Neutrons (most common/stable nuclide): 157
  • Number of Protons: 108
  • Oxidation States:
  • Valence Electrons:

Chemical Properties

  • Electrochemical Equivalent:
  • Electron Work Function:
  • Electronegativity: N/A (Pauling); N/A (Allrod Rochow)
  • Heat of Fusion: kJ/mol
  • Incompatibilities:
  • Ionization Potential
    • First:
  • Valence Electron Potential (-eV):

Physical Properties

  • Atomic Mass Average: 265
  • Boiling Point:
  • Coefficient of Lineal Thermal Expansion/K-1: N/A
  • Conductivity
    Electrical:
    Thermal:
  • Description:
    Man made radioactive metal.
  • Flammablity Class:
  • Freezing Point: see melting point
  • Heat of Vaporization: kJ/mol
  • Melting Point:
  • Physical State (at 20C & 1atm):
  • Specific Heat:
  • Vapor Pressure:

Regulatory / Health

  • CAS Number
    • 54037-57-9
  • NFPA 704
    • Health:
    • Fire:
    • Reactivity:
    • Special Hazard: Radioactive<
    • OSHA Permissible Exposure Limit (PEL)
      • No limits set by OSHA
    • OSHA PEL Vacated 1989
      • No limits set by OSHA
    • NIOSH Recommended Exposure Limit (REL)
      • No limits set by NIOSH
    • Levels In Humans:
      Note: this data represents naturally occuring levels of elements in the typical human, it DOES NOT represent recommended daily allowances.
      • Blood/mg dm-3: nil
      • Bone/p.p.m: nil
      • Liver/p.p.m: nil
      • Muscle/p.p.m: nil
      • Daily Dietary Intake: nil
      • Total Mass In Avg. 70kg human: nil

    Who / Where / When / How

    • Discoverer: Peter Armbruster, Gottfried Munzenber, et al.
    • Discovery Location: Darmstadt, Germany
    • Discovery Year: 1984
    • Name Origin:
      Latin "Hassias" meaning "Hess", the German state.
    • Abundance:
      • Earth's Crust/p.p.m.: N/A
      • Seawater/p.p.m.: nil
      • Atmosphere/p.p.m.: N/A
      • Sun (Relative to H=1E12): N/A
    • Sources:
      Synthetically prepared element. Only a small number of atoms have every been produced.
    • Uses:
      None
    • Additional Notes:
      In August of 1997 the International Union of Pure and Applied Chemistry announced the official naming of this element as Hassium

Transition Metals
Group 3
(IIIB)
4
(IVB)
5
(VB)
6
(VIB)
7
(VIIB)
8
(VIIIB)
9
(VIIIB)
10 (VIIIB) 11
(IB)
12
(IIB)
Period 4 21
Sc
44.95
22
Ti
47.86
23
V
50.94
24
Cr
51.99
25
Mn
54.93
26
Fe
55.84
27
Co
58.93
28
Ni
58.69
29
Cu
63.54
30
Zn
65.39
Period 5 39
Y
88.90
40
Zr
91.22
41
Nb
92.90
42
Mo
95.94
43
Tc
98.00
44
Ru
101.0
45
Rh
102.9
46
Pd
106.4
47
Ag
107.8
48
Cd
112.4
Period 6 57
La
138.9
72
Hf
178.4
73
Ta
180.9
74
W
183.8
75
Re
186.2
76
Os
190.2
77
Ir
192.2
78
Pt
195.0
79
Au
196.9
80
Hg
200.5
Period 7 89
Ac
227.0
104
Rf
261.0
105
Db
262.0
106
Sg
266.0
107
Bh
264.0
108
Hs
269.0
109
Mt
268.0
110
Ds
269.0
111
Rg
272.0
112
Uub
277.0