Science Fair Project Encyclopedia |Name, Symbol,
Number||selenium, Se, 34| |Group, Period, Block||16 (VIA), 4, p|
|Density, Hardness||4790 kg/m3(300K), 2| |Appearance|| grey,
metallic lustre| |Atomic weight||78.96 amu| |Atomic radius
(calc.)||115 (103) pm| |Covalent radius||116 pm| |van der Waals
radius||190 pm| |e- 's per energy level||2, 8, 18, 6| |Oxidation
states (Oxide)||±2,4,6 (strong acid)| |State of matter||solid
(__)| |Melting point||494 K (430 °F)| |Boiling point||957.8 K
(1265 °F)| |Molar volume||16.42 ×10-6 m3/mol| |Heat of
vaporization||26.3 kJ/mol| |Heat of fusion||6.694 kJ/mol| |Vapor
pressure||0.695 Pa at 494 K| |Speed of sound||3350 m/s at 293.15
K| |Electronegativity||2.48 (Pauling scale)| |Specific heat
capacity||320 J/(kg*K)| |Electrical conductivity||1.0E-10
106/(m·ohm)| |Thermal conductivity||2.04 W/(m*K)| |1st
ionization potential||941 kJ/mol| |2nd ionization
potential||2045 kJ/mol| |3rd ionization potential||2973.7
kJ/mol| |4th ionization potential||4144 kJ/mol| |Most stable
isotopes|