Protactinium

Notable Characteristics

Protactinium is a silver superconductive at temperatures below 1.4 K.

Applications

Due to its scarcity, high radioactivity and toxicity, there are currently no uses for protactinium outside of basic scientific research.

Protactinium-231 (which is formed by the critical mass, according to Walter Seifritz, is 750±180 kg. Other authors conclude that no chain reactions are possible in Protactinium-231.

History

An element between William Crookes isolated protactinium as a radioactive material from uranium which he could not identify^[1].

Protactinium was first identified in 1913, when Frederick Soddy and John Cranston of the UK) independently discovered 231-Pa. The name was shortened to Protactinium in 1949.

Aristid V. Grosse prepared 2 mg of Pa₂O₅ in 1927, and later on managed to isolate Protactinium for the first time in 1934 from 0.1 mg of Pa₂O₅, first converting the oxide to an iodide and then cracking it in a high vacuum by an electrically heated filament by the reaction 2PaI₅ → 2Pa + 5I₂ (iodide process).

In 1961, the United Kingdom Atomic Energy Authority was able to produce 125 g of 99.9% pure protactinium, processing 60 tons of waste material in a 12-stage process and spending 500,000 USD. For many years to come, this was the world's only supply of the element. It is reported that the metal was sold to laboratories for a cost of 2,800 USD / g in the following years.^{[citations needed]}

Occurrence

Protactinium occurs in ppm). Some ores from the Democratic Republic of the Congo have about 3 ppm.

Compounds

Known Protactinium compounds:

• Fluorides: PaF₄, PaF₅
• Chlorides: PaCl₄, PaCl₅
• Bromides: PaBr₄, PaBr₅
• Iodides: PaI₃, PaI₄, PaI₅
• Oxides: PaO, PaO₂, Pa₂O₅

See also: Compounds of Protactinium

Isotopes

Main article: isotopes of protactinium

29 radioactive isotopes have half-lifes that are less than 1.6 days, and the majority of these have half lifes that are less than 1.8 seconds. This element also has 2 meta states, 217m-Pa (t_½ 1.15 milliseconds) and 234m-Pa (t_½ 1.17 minutes).

The primary uranium) isotopes.

Precautions

Protactinium is both toxic and highly radioactive. It requires precautions similar to those used when handling plutonium.

References