Plutonium (Pu)
"The Planet-Hopper, the hero who powers deep-space missions to the outer planets."
A memorable persona to anchor Pu in your mind.
19.816
Grams per cm³
640
Celsius (°C)
243
Radius (pm)
Daily Life Link
Plutonium is found as the power source for deep-space probes like the Voyager spacecraft.
Discovery & History
Year Discovered
1940
Discovered By
Glenn Seaborg and colleagues
Origin of Name
"Plutonium, is named after the then planet Pluto, following from the two previous elements uranium and neptunium."
Technical Properties
Atomic Mass
[244] u
Standard State
solid
Boiling Point
3228°C
Electron Configuration
[Rn] 5f67s2
1st Ionization Energy
6.06 eV
Electron Affinity
N/A
Oxidation States
"Plutonium is a silvery-gray, radioactive metal."
Did You Know?
It was named after the dwarf planet Pluto, continuing the planetary theme after uranium and neptunium.
The 'Fat Man' atomic bomb dropped on Nagasaki in 1945 used a core of plutonium-239.
The radioisotope thermoelectric generators (RTGs) that power deep space probes like the Voyager and Cassini spacecraft use the heat from the radioactive decay of plutonium-238.
It has the unusual property that its density increases as it is heated over a certain temperature range.