Plutonium was the second transuranium element of the actinide series to be discovered. By far of greatest importance is the isotope239Pu, which has a half-life of more than 20000 years. One kilogram is equivalent to about 22 million kilowatt hours of heat energy. The complete detonation of a kilogram of plutonium produces an explosion equal to about 20000 tons of chemical explosive. The various nuclear applications of plutonium are well known. The isotope233Pu was used in the American Apollo lunar missions to power seismic and other equipment on the lunar surface. Plutonium contamination is an emotive environmental problem.
Plutonium dioxide, PuO2. Image adapted with permission fromProf James Marshall's (U. North Texas, USA)Walking Tour of the elements CD.
Binary compounds with halogens (known as halides), oxygen (known as oxides), hydrogen (known as hydrides), and other compounds of plutonium where known.
Density of solid: 19816 kg m-3
Molar volume: 12.29 cm3
Thermal conductivity: 6 W m‑1 K‑1
Melting point: 912.5 [639.4 °C (1182.9 °F)] K
Boiling point: 3503 [3230 °C (5846 °F)] K
Enthalpy of fusion: 20.5 kJ mol-1
Atomic radius (empirical): 175 pm
Molecular single bond covalent radius: 172 (coordination number 3) ppm
van der Waals radius: (no data) ppm
Pauling electronegativity: 1.28 (Pauling units)
Allred Rochow electronegativity: 1.22 (Pauling units)
Mulliken-Jaffe electronegativity: (no data)
First ionisation energy: 581.40 kJ mol‑1
Second ionisation energy: 1110 kJ mol‑1
Third ionisation energy: 2040 kJ mol‑1
Universe: (no data) ppb by weight
Crustal rocks: (no data) ppb by weight
Human: (no data) ppb by weight
