• Name: Thallium

  • Symbol: Tl

  • Number of Energy Levels: 6

  • Electrons on the outer energy level: 3

  • Atomic Number: 81

  • Atomic Mass: 204.38 Amu

  • Protons / Electrons: 81

  • Neutrons: 123

  • Density: 11.85 g/cm3

  • Classification: Other Metals

Top 12 interesting facts about Thallium

  • Thallium was discovered in 1861 by Sir William Crookes. Its name derives from the Greek word "thallos" which means "young shoot".
  • Thallium's melting point is at 303.5 C (576.65 K, 578.3 F) and its boiling point is at 1457.0 C (1730.15 K, 2654.6 F).
  • Thallium has a gray color and it is a soft and ductile metal.
  • Thallium tarnishes when exposed to air and reacts with water.
  • Thallium is not found freely in nature.
  • Thallium is produced as a byproduct of refining sulfide ores.
  • Thallium has two stable isotopes: 203-Tl and 205-Tl.
  • Thallium is mainly used in electronic industry for photo-resistors production and for infrared and gamma radiation detection devices.
  • Thallium is used in research and production of high-temperature superconducting materials.
  • Thallium is also used in optics industry for producing glasses with a high index of refraction and glasses with a high density.
  • Thallium is used in different niche applications such as nuclear medicine, thermometers and low-temperature switches (mercury-thallium alloy), in anodes of seawater batteries, and few others.
  • Thallium and its compounds are very toxic.