Subscription Info   Newsletter   Site Demo   Librarians   Help/FAQs   About   Contact Us   
Search Options

  Log In
< Back

Selenium  SEE PERIODIC TABLE
see article  SEE FULL ARTICLE


Atomic Number34

Atomic SymbolSe

Atomic Weight78.96 amu

GroupNon-Metal, 16

FormSolid

Density @ STP4.81 g/cm3

Melting Point180 °C (356 °F, 453.15 °K)

Boiling Point685 °C (1265 °F, 958.15 °K)

Heat of Fusion6.69 kJ/mol

Heat of Vaporization95.48 kJ/mol

First Ionization Potential9.75238 eV

Electronegativity (on Pauling scale)2.55

Specific Heat Capacity0.321 J/g K

Ground State Electron Configuration4p4

Oxidation States+4, +6, -2

Stable Isotopes and Natural Abundance on Earth74Se, 0.89%; 76Se, 9.36%; 77Se, 7.63%; 78Se, 23.78%; 80Se, 49.61%; 82Se, 8.73%

Selected Radioisotopes72Se, 75Se, 79Se

Atomic Radius103 pm

Crystal StructureMonoclinic

Discovered byBerzelius, 1817

Copyright ©2008 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use and Privacy Notice.
Additional credits and copyright information.