• Name: Actinium

  • Symbol: Ac

  • Number of Energy Levels: 7

  • Electrons on the outer energy level: 2

  • Atomic Number: 89

  • Atomic Mass: 227.0 Amu

  • Protons / Electrons: 89

  • Neutrons: 138

  • Density: 10.07 g/cm3

  • Classification: Rare Earth

Top 12 interesting facts about Actinium

  • Actinium was discovered in 1899 by Andre Debierne. Its name derives from the Greek word "aktinos" which means "ray".
  • Actinium's melting point is at 1050.0 C (1323.15 K, 1922.0 F) and its boiling point is at 3200.0 C (3473.15 K, 5792.0 F).
  • Actinium is a radioactive element.
  • Actinium is a soft silvery-white metal.
  • Actinium glows blue in the dark due to its radioactivity.
  • Actinium has similar chemical properties as lanthanum.
  • Actinium gave the name to actinide series of elements (15 elements with similar characteristics placed between actinium and lawrencium in periodic table).
  • Actinium reacts with the oxygen from the air forming a white coating of actinium oxide which prevents further oxidation.
  • Actinium has a very limited number of compounds.
  • Actinium has 36 unstable isotopes; two of them occurring naturally.
  • Actinium is found in very small quantities in uranium and thorium ores.
  • Actinium is used in very few applications such as neutron source and in medicine for radiation therapy for cancer treatment.