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Name: Thallium
Symbol: Tl
Number of Energy Levels: 6
Electrons on the outer energy level: 3
Atomic number: 81
Atomic Mass: 204.38 Amu (Atomic Mass Units)
Protons/Electrons: 81
Neutrons: 123
Density: 11.85 g/cm3
Classification: Other Metals

Thallium | Chemical elements

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).

Top 10 interesting facts about Thallium

  1. Thallium has a gray color and it is a soft and ductile metal.
  2. Thallium tarnishes when exposed to air and reacts with water.
  3. Thallium is not found freely in nature.
  4. Thallium is produced as a byproduct of refining sulfide ores.
  5. Thallium has two stable isotopes: 203-Tl and 205-Tl.
  6. Thallium is mainly used in electronic industry for photo-resistors production and for infrared and gamma radiation detection devices.
  7. Thallium is used in research and production of high-temperature superconducting materials.
  8. Thallium is also used in optics industry for producing glasses with a high index of refraction and glasses with a high density.
  9. 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.
  10. Thallium and its compounds are very toxic.

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