The Transuranium Elements! 
By GLENN T. SEABORG 
Chancellor, University of California 
Berkeley 
[With 1 plate] 
Tue stupy of the transuranium elements is an exciting branch of 
science, which started less than 20 years ago and has a clearly discerni- 
ble future of great expansion. These elements represent the realization 
of the alchemists’ dream of transmutation. They have played an 
important role in the recent renaissance of inorganic chemistry. An 
advance as fundamental as a 10-percent increase in the number of 
chemical elements has, as one might anticipate, contributed much to 
our fund of the most basic scientific knowledge, especially in the 
fields of chemistry and physics. 
The chemistry and physics of the longer known transuranium ele- 
ments are already remarkably developed, and extremely interesting. 
Neptunium has an isotope sufficiently long lived to be safe to handle 
with moderate precautions in ordinary laboratories; plutonium and 
curium have similarly long-lived isotopes which should eventually 
make these elements available for broader investigation throughout 
the world when they become more available. One of the transuranium 
elements, plutonium, is particularly interesting. It has an isotope 
with nuclear properties such that it is destined to play an extremely 
important role in the history of mankind. Plutonium was discovered 
and methods for its manufacture were worked out under the cloak 
of secrecy during the last war. It was the first synthetic element to be 
seen by man and the first example of large-scale production of an 
element by transmutation. Plutonium has most unusual chemical 
and metallurgical properties. For example, it has four oxidation 
states which may exist in aqueous solution in equilibrium with each 
other at appreciable concentrations. The metallic form has six 
allotropic modifications between room temperature and its melting 
point, some with properties unknown in any other metal. The 
alpha-radioactivity and physiological behavior of its fissionable iso- 
1 Reprinted by permission from Endeavour, vol. 18, No. 69, January 1959. 
536608—60——_17 247 
