Number of Energy Levels: 4
Electrons on the outer energy level: 6
Atomic number: 34
Atomic Mass: 78.96 Amu (Atomic Mass Units)
Density: 4.79 g/cm3
Selenium was discovered in 1817 by Jons Berzelius. Its name drives from the Greek word "selene" (which means Moon). Selenium’s melting point is at 217.0 °C (490.15 K, 422.6 °F) and its boiling point is at 684.9 °C (958.05005 K, 1264.8201 °F).
Top 15 interesting facts about selenium
Selenium can rarely be found in its elemental state in nature.
Usually, selenium is a byproduct obtained during cooper production.
Selenium has six naturally occurring isotopes, five of them being stable: 74-Se, 76Se, 77-Se, 78-Se, 80-Se, and 82-Se.
Because selenium has many similarities with tellurium (named for the Earth), Berzelius named the new element selenium (which is the name for the Moon).
Selenium occurs naturally is selenide-containing minerals (and other such minerals) but they are rare.
Selenium is usually found in sulfide ores, replacing a small amount of the sulfur.
It is said that the ocean water contains significant amounts of selenium.
Selenium is also found in many living organism and its role is the same as of sulfur.
Every year, about 2000 tones of selenium are produced.
The biggest producers of selenium are: Germany, Japan, the USA, and China.
Most of the selenium is used in metallurgy and glass production.
China consumes the largest part of all selenium produced in the world.
Selenium is used in alloys replacing the more toxic lead.
Selenium is also a component in solar cell production.
Tolerable intake amount of selenium is 400 micro-grams/day.