Chemical Elements.com - Selenium (Se)

Show Table With:
   Name
   Atomic Number
   Atomic Mass
   Electron Configuration
   Number of Neutrons
   Melting Point
   Boiling Point
   Date of Discovery
   Crystal Structure

Element Groups:
   Alkali Metals
   Alkaline Earth Metals
   Transition Metals
   Other Metals
   Metalloids
   Non-Metals
   Halogens
   Noble Gases
   Rare Earth Elements

Basic Information | Atomic Structure | Isotopes | Related Links | Citing This Page

Basic Information

Name: Selenium
Symbol: Se
Atomic Number: 34
Atomic Mass: 78.96 amu
Melting Point: 217.0 °C (490.15 K, 422.6 °F)
Boiling Point: 684.9 °C (958.05005 K, 1264.8201 °F)
Number of Protons/Electrons: 34
Number of Neutrons: 45
Classification: Non-metal
Crystal Structure: Hexagonal
Density @ 293 K: 4.79 g/cm³
Color: gray

Atomic Structure

Number of Energy Levels: 4

First Energy Level:

Second Energy Level:

Third Energy Level:

Fourth Energy Level:

Isotopes

Isotope	Half Life
Se-73	7.15 hours
Se-74	Stable
Se-75	119.78 days
Se-76	Stable
Se-77	Stable
Se-78	Stable
Se-79	65000.0 years
Se-80	Stable
Se-82	Stable

Facts

Date of Discovery: 1817
Discoverer: Jons Berzelius
Name Origin: From the Greek word Sel�n� (Moon)
Uses: photoelectric cells, TV cameras
Obtained From: refining of lead, copper, nickel

MLA Format for Citing This Page

Bentor, Yinon. Chemical Element.com - Selenium. <http://www.chemicalelements.com/elements/se.html>.

For more information about citing online sources, please visit the MLA's Website.