A Visual Encyclopedia of the Periodic Table

104

Transition Metals

Bohrium

Bh

107

Hassium

Hs

108

Bohrium is an artificial

element named after the

Danish scientist Niels Bohr.

This was to honour his model

of the structure of atoms’

electron shells. Bohrium

was first produced by firing

chromium atoms at bismuth

atoms in a particle accelerator

(a machine in which atoms are

smashed together). Atoms

of this metal are unstable:

half of any sample of bohrium

atoms breaks apart in 61

seconds. As a result, it is

not very well understood.

Scientists think hassium

is a metal, but they have

not been able to produce

enough of its atoms to study

it in any detail. Hassium is

very radioactive, and most of

its atoms break apart within a

few seconds. This element is

named after the German state

of Hesse, the location of

the Centre for Heavy Ion

Research, where hassium

was first created artificially

by a team led by the German

physicist Peter Armbruster.

Niels Bohr

Peter Armbruster

A chamber at Centre

for Heavy Ion Research,

Darmstadt, Germany

Hassium was produced

inside this chamber.

108 108 169

State: Solid

Discovery: 1984

107 107 163

State: Solid

Discovery: 1981

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