Plumtonium is a highly radioactive element and it should be handled with extreme caution. It is used in a variety of applications, including the nuclear bomb “Fat Man” that was dropped on Nagasaki during World War II and in the Curiosity Mars rover to power its batteries.

The structure of plutonium is complex, but it can be characterized using many different techniques. This includes single-crystal X-ray diffraction (XRD), extended X-ray absorption fine structure (EXAFS), and theoretical calculations.

When dissolved in water, plutonium exhibits five ionic valence states: Pu+3 (blue lavender), Pu+4 (salmon-colored), PuO+ (lavender), PuO+2 (orange-brown), and PuOxOHy (dark green in basic solution).

At room temperature alpha form is as hard and brittle as cast iron, but alloyed with other metals it forms the room-temperature stabilized delta phase which makes it soft and ductile. It is not a good conductor of heat or electricity, has a low melting point (640 degC) and an unusually high boiling point (3,230degC).

Plutonium can be very sensitive to changes in temperature, pressure, or chemistry. It can undergo dramatic volume changes following a phase transition.

It also oxidizes quickly, forming pyrophoric surfaces that can burn in air. This characteristic led to two catastrophic fires at the Rocky Flats Plant in 1957 and 1969 that caused tens of millions of dollars in damage.

In the nuclear fuel reprocessing, waste management, and radionuclide decontamination fields the oxidation states of actinides are crucial in understanding their behavior at the molecular level. This is particularly true when atypical oxidation states are achieved, as this requires the development of new organic ligands that can capture and carry the lower oxidation state while still retaining the higher one.