A Visual Encyclopedia of the Periodic Table

102

Transition Metals

Rutherfordium

Rf

104

Dubnium

Db

105

Rutherfordium was the first superheavy

element to be discovered. In this type

of element, each atom has 104 or more protons

in its nucleus. It is named after the New Zealand

scientist Ernest Rutherford, who, in 1913,

suggested that every atom has a nucleus, or

core. Pure rutherfordium is synthesized by

researchers in a laboratory.

It took scientists nearly 30 years to agree on

a name for this element. Dubnium was finally

named after the Russian city of Dubna, where the

first atoms of this artificial, radioactive element

were created, in 1968. However, a team of

American scientists led by Albert Ghiorso also

produced samples of the element at the same

time. This radioactive element has 12 isotopes,

or forms, with different numbers of neutrons.

The US

scientist Albert

Ghiorso discovered

12 elements

in the 20th

century.

Ernest Rutherford

Albert Ghiorso

State: Solid

Discovery: 1968

105 105 163

104 104 163

State: Solid

Discovery: 1964

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