Plutonium is a radioactive metallic element. Although it is occasionally
its solid state until very high temperatures, melting at six hundred and forty
degrees Celsius, and boiling at three thousand four hundred and sixty degrees.
The density of Plutonium, at twenty degrees centigrade, is 19.86 grams per cubic
and his associate Edward M. McMillan. The two shared the Nobel prize in 1951
for their discoveries of Plutonium, Americium (Am), Curium (Cm), Berkelium (Bk),
and Californium (Cf). In addition, Seaborg later contributed to the discovery
Nobelium (No). Plutonium was Seaborg?s first discovery. Its name came from
Shortly after, Seaborg was able to isolate plutonium 239, an isotope used in
Plutonium is a highly dangerous and poisonous element because it rapidly
gives off radiation in the form of alpha particles. Alpha particles, which are
identical to the nucleus of a helium atom, consist of two protons and two
neutrons tightly bound together. Although the particles can only travel about
radiation, Plutonium will spontaneously explode when a certain amount, called
critical mass, is kept together. Soon after the discovery of Plutonium, it was
in oxidation states of +3, +4, +5, and +6.
Currently, there are fifteen known isotopes of Plutonium, with mass
numbers ranging between 232 and 246. The most important isotope is plutonium 239,
fission. In fission, When struck by a neutron, the nucleus of the plutonium atom
energy released by one atom is not much, the splitting of the nucleus releases
more neutrons, which strike more plutonium atoms. This process, called a chain-
reaction, produces enormous amounts of energy. This energy is often used to
Pu-239 is such an efficient use for energy, disposing of its waste has become a
major problem. When uranium is converted to Pu-239, a waste with a half-life of
around 24,100 years is produced.
actually getting the chain-reaction to work. Often, only the first few atoms
struck by the deuterons convert to Plutonium. Unfortunately for the scientists,
fission capture by uranium, 3) non-fission capture by impurities, and 4) fission
capture. The first three factors cause the uranium to lose neutrons, the last
produced, by fission capture, the reaction occurs. Otherwise, plutonium is not
made, and the chain-reaction stops immediately.
Using the chain-reaction system, the first operating nuclear reactor of
a reasonable amount of power was built in 1943. It was called the X-10 reactor.
The core of the reactor was a twenty- four foot cube of graphite blocks, with
1248 fuel channels each 1.75 inches square. Each hole was fueled with four inch
long uranium rod, jacketed in aluminum to protect against oxidation. The entire
core was surrounded by a seven-foot thick concrete shield, with openings at one
end to replace the uranium rods. At a cost of $1,000,000 for the building and
$2,000,000 each for the graphite and uranium, this plant produce about 190 Mevs
In addition to its uses as fuel for a reactor or in a bomb, plutonium
hearts. Also, isotopes Pu-242 and Pu-244, which occurs naturally, are used in
studying chemicals and metals.
The half-life of atoms of plutonium was very important to seaborg and
his assistants back in 1940. In fact, all of his other radioactive discoveries
were based on the finding of Pu-238. For example, Pu-241 decays with a half-life
of about thirteen years emitting negatively charged beta particles, or electrons.
It then converts to Am-241, an isotope of americium, which emits alpha particles
for 470 years, before turning into Am-242, which converts to Cm-242, an isotope
of curium, in only sixteen hours. The Cm-242 emits alpha particles for about 162
days before ending the decay of Plutonium 241.
Chemical Equation for Producing Plutonium: 92U-238 —-> 92U-
-239 —-> 93Np-239 —-> 94Pu-239