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Selenium (Se)
Atomic number: 34 · Category: polyatomic nonmetal · Group 16 · Period 4 · Phase: Solid
Selenium is a chemical element with symbol Se and atomic number 34. It is a nonmetal with properties that are intermediate between those of its periodic table column-adjacent chalcogen elements sulfur and tellurium. It rarely occurs in its elemental state in nature, or as pure ore compounds.
Atomic mass: 78.9718
Density: 4.81
Melting point: 494 K
Boiling point: 958 K
Appearance: black, red, and gray (not pictured) allotropes
Source: Wikipedia
Block: p
Molar heat: 25.363
CPK color:#ffa100
Electronic structure
Electron configuration: 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p4
Configuration (semantic): [Ar] 3d10 4s2 4p4
Shells: 2, 8, 18, 6
Electronegativity (Pauling): 2.55
Electron affinity: 194.9587
Ionization energies: 941, 2045, 2973.7, 4144, 6590, 7880, 14990
Periodic position
Group: 16
Period: 4
xpos: 16
ypos: 4
Spectral/Bohr images
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3D Model