protoactinium
A scientist carefully handles a sample of protoactinium in a secure laboratory.
Noun: A short-lived, radioactive, metallic chemical element. It is formed from the decay of uranium and itself decays into actinium and then ultimately into lead. It is a dense, silvery-gray metal that is highly toxic due to its radioactivity.
"Protoactinium" is the original name for the element now more commonly known as "protactinium." It is used primarily in scientific, historical, and technical contexts when discussing the discovery, properties, or nuclear decay chains of radioactive elements. * The element protoactinium was identified in the decay chain of uranium. * Research on protoactinium helped scientists understand the actinide series of elements.
- In nuclear chemistry: The isotope Pa-231 is a significant decay product in the uranium-235 series and is studied for its nuclear properties.
- The half-life of protoactinium-231 is approximately 32,760 years.
- Protactinium (n): The modern, standard name for the element (symbol Pa, atomic number 91). "Protoactinium" and "protactinium" refer to the same element.
- The periodic table lists the element as protactinium.
- Element 91: A synonym based on its atomic number.
- Pa: Its chemical symbol.
The word "protoactinium" is formed from the prefix "proto-" (meaning first or precursor) and "actinium," indicating it decays into actinium. Its meaning is highly specific to the field of chemistry and nuclear physics.
A scientist carefully handles a sample of protoactinium in a secure laboratory.
- a short-lived radioactive metallic element formed from uranium and disintegrating into actinium and then into lead