How many isotopes does protactinium have?

How many isotopes does protactinium have?

Twenty-nine radioisotopes of protactinium have been discovered. Nearly all naturally occurring protactinium is 231Pa with a half-life of 32,700 years.

What are two different isotopes of protactinium?

Protactinium is one of the rarest and most expensive naturally occurring elements. It is found in the form of two isotopes – 231Pa and 234Pa, with the isotope 234Pa occurring in two different energy states.

What compounds is protactinium found in?


  • Protactinium tetrachloride: PaCl4
  • Protactinium pentachloride: PaCl5

What is protactinium mostly used for?

Protactinium is used mainly for research purposes. Protactinium-231 combined with the thorium-230 can be used to date marine sediments.

Is protactinium man made?

All 29 isotopes are radioactive; synthetic protactinium-233 is produced by neutron irradiation of thorium-232 after it is converted to thorium-233 and is the progenitor of the fissile uranium isotope uranium-233 in the production of nuclear fuel from thorium.

Which is the only naturally occurring isotope of protactinium?

The only naturally occurring isotopes are 231 Pa, which occurs as an intermediate decay product of 235 U, 234 Pa and 234m Pa, both of which occur as intermediate decay products of 238 U. 231 Pa makes up nearly all natural protactinium.

How did the element protactinium get its name?

The name derives from the Greek protos (first) for preceding the element actinium, because its most common isotope ( 231 Pa) decays to 227 Ac by loss of an alpha particle.

Where can protactinium be found in the world?

Source: Protactinium occurs naturally in minute amounts (up to 3 parts per million) in uranium ores. Protactinium can also obtained as a by-product of uranium processing. Isotopes: Protactinium has 27 isotopes whose half-lives are known, with mass numbers 212 to 238. Protactinium has no stable isotopes.

Where does uranium 238 get its protactinium isomer?

Nearly all uranium-238 (99.8%) decays first to the 234m Pa isomer and then to 234 Pa. Smaller trace amounts of the short-lived nuclear isomer protactinium-234m occur in the decay chain of uranium-238.