What is plutonium?
A: Plutonium is a radioactive chemical element with the symbol Pu and atomic
number 94.
It is an actinide metal of silvery-gray appearance that
tarnishes when exposed to what?
A: Air and forms a dull coating when oxidized.
The element normally exhibits six allotropes and how
many oxidation states?
A: Four.
What does it react with?
A: Carbon, halogens, nitrogen, silicon, and hydrogen.
When exposed to moist air, it forms what?
A: Oxides and hydrides.
It is radioactive and can accumulate in what?
A: Bones, which makes the handling of plutonium dangerous.
When was plutonium first synthetically produced and
isolated?
A: In late 1940 and early 1941.
How was it produced?
A: By a deuteron bombardment of uranium-238.
Where was it produced?
A: In the 1.5-metre (60 in) cyclotron at the University of
California,
Berkeley.
Since uranium had been named after the planet Uranus
and neptunium after the planet Neptune, element 94 was named after what?
A: Pluto, which at the time was considered a planet as well.
Wartime secrecy prevented the University of California
team from publishing its discovery until when?
A: 1948.
Plutonium is the element with the highest atomic number
to occur where?
A: In nature.
Trace quantities arise in natural uranium-238 deposits
when uranium-238 does what?
A: Captures neutrons emitted by decay of other uranium-238 atoms.
Both plutonium-239 and plutonium-241 are fissile,
meaning what?
A: That they can sustain a nuclear chain reaction, leading to applications
in nuclear weapons and nuclear reactors.
The presence of plutonium-240 limits a plutonium
sample's usability for what?
A: Weapons or its quality as reactor fuel.
The percentage of plutonium-240 determines its what?
A: Its grade (weapons-grade, fuel-grade, or reactor-grade).
What is the half-life of Plutonium-238.
A: It has a half-life of 87.7 years and emits alpha
particles.
It is a heat source in radioisotope thermoelectric
generators, which are used for what?
A: To power some spacecraft.
Plutonium isotopes are expensive and inconvenient to
separate, so particular isotopes are usually manufactured where?
A: In specialized reactors.
Producing plutonium in useful quantities for the first
time was a major part of what?
A: The Manhattan Project during World War II that developed the first atomic
bombs.
Which early atomic bombs had plutonium cores?
A: The Fat Man bombs used in the Trinity nuclear test in July 1945, and in
the bombing of Nagasaki in August 1945, had plutonium cores.
Human radiation experiments studying plutonium were
conducted without what?
A: Without informed consent.
Disposal of plutonium waste from nuclear power plants
and dismantled nuclear weapons built during the Cold War is what?
A: A nuclear-proliferation and environmental concern.
Unlike most metals, it is not a good conductor of what?
A: Heat or electricity.
It has a low melting point (640 °C, 1,184 °F) and an
unusually high what?
A: Boiling point (3,228 °C, 5,842 °F).
What is the most common form of radioactive decay for
plutonium?
A: Alpha decay, the release of a high-energy helium nucleus,
A 5 kg mass of 239Pu contains about how many atoms?
A: 12.5×1024.
With a half-life of 24,100 years, about 11.5×1012 of
its atoms decay each second by doing what?
A: By emitting a 5.157 MeV alpha particle.
This amounts to how many watts of power?
A: 9.68 watts.
Heat produced by the deceleration of these alpha
particles makes it what?
A: Warm to the touch.