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Name: Protactinium
Symbol: Pa
Number of Energy Levels: 7
Electrons on the outer energy level: 2
Atomic number: 91
Atomic Mass: 231.03 Amu (Atomic Mass Units)
Protons/Electrons: 91
Neutrons: 140
Density: 15.4 g/cm3
Classification: Rare Earth

Protactinium | Chemical elements

Protactinium was discovered in 1917 by Otto Hahn and Lise Meitner. Its name derives from the Greek word "protos" which means "first". Protactinium’s melting point is at 1600.0 °C (1873.15 K, 2912.0 °F) and its boiling point is believed to be at 4027 °C.

Top 9 interesting facts about Protactinium

  1. Protactinium is a dense chemical element.
  2. Protactinium has a silvery-gray color.
  3. Protactinium reacts with oxygen and water.
  4. Protactinium is denser than thorium but lighter than uranium.
  5. Protactinium is used just for research purposes.
  6. Protactinium is found in Earth’s crust mostly in some uranite ores.
  7. Protactinium is mostly produced from spent nuclear fuel as an intermediate product of nuclear fission in thorium reactors.
  8. Protactinium has 29 radioisotopes (all unstable but the most stable isotope is 231- Protactinium).
  9. Protactinium is highly radioactive and very toxic.

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