మూస:సెలీనియం మూలకము

సెలీనియం, ₀₀Se
సెలీనియం
Pronunciation	/sɪˈliːniəm/ (sə-LEE-nee-əm)
Appearance	black and red allotropes
Standard atomic weight Ar°(Se)
	78.971±0.008; 78.971±0.008 (abridged);
సెలీనియం in the periodic table
	ఆర్సెనిక్ ← సెలీనియం → బ్రోమిన్
Group	మూస:Infobox element/symbol-to-group/format
Period	period 4
Block	p-block
Electron configuration	[Ar] 3d10 4s2 4p4
Electrons per shell	2, 8, 18, 6
Physical properties
Phase at STP	solid
Melting point	494 K (221 °C, 430 °F)
Boiling point	958 K (685 °C, 1265 °F)
Density (near r.t.)	(gray) 4.81 g/cm3 ; (alpha) 4.39 g/cm3 ; (vitreous) 4.28 g/cm3
when liquid (at m.p.)	3.99 g/cm3
Critical point	1766 K, 27.2 MPa
Heat of fusion	(gray) 6.69 kJ/mol
Heat of vaporization	95.48 kJ/mol
Molar heat capacity	25.363 J/(mol·K)
Atomic properties
Oxidation states	−2, −1, 0, +1, +2, +3, +4, +5, +6 (a strongly acidic oxide)
Electronegativity	Pauling scale: 2.55
Atomic radius	empirical: 120 pm
Covalent radius	120±4 pm
Van der Waals radius	190 pm
	Spectral lines of సెలీనియం
Other properties
Natural occurrence	primordial
Crystal structure	hexagonal
Speed of sound thin rod	3350 m/s (at 20 °C)
Thermal expansion	(amorphous) 37 µm/(m⋅K) (at 25 °C)
Thermal conductivity	(amorphous) 0.519 W/(m⋅K)
Magnetic ordering	diamagnetic
Young's modulus	10 GPa
Shear modulus	3.7 GPa
Bulk modulus	8.3 GPa
Poisson ratio	0.33
Mohs hardness	2.0
Brinell hardness	736 MPa
CAS Number	7782-49-2
History
Discovery	Jöns Jakob Berzelius and Johann Gottlieb Gahn (1817)
First isolation	Jöns Jakob Berzelius and Johann Gottlieb Gahn (1817)
Isotopes of సెలీనియం v; e;
	Template:infobox సెలీనియం isotopes does not exist
	Category: సెలీనియం; view; talk; edit; \| references

References

↑ "Standard Atomic Weights: Selenium". CIAAW. 2013.
↑ Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; et al. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry (in ఇంగ్లీష్). doi:10.1515/pac-2019-0603. ISSN 1365-3075.
↑ A Se(0) atom has been identified using DFT in [ReOSe(2-pySe)₃]; see Cargnelutti, Roberta; Lang, Ernesto S.; Piquini, Paulo; Abram, Ulrich (2014). "Synthesis and structure of [ReOSe(2-Se-py)3]: A rhenium(V) complex with selenium(0) as a ligand". Inorganic Chemistry Communications. 45: 48–50. doi:10.1016/j.inoche.2014.04.003. ISSN 1387-7003.
↑ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 0080379419.
↑ Magnetic susceptibility of the elements and inorganic compounds, in Lide, D. R., ed. (2005). CRC Handbook of Chemistry and Physics (86th ed.). Boca Raton (FL): CRC Press. ISBN 0-8493-0486-5.
↑ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 0080379419.

[1] "Standard Atomic Weights: Selenium". CIAAW. 2013.

[CIAAW2021-2] Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; et al. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry (in ఇంగ్లీష్). doi:10.1515/pac-2019-0603. ISSN 1365-3075.

[3] A Se(0) atom has been identified using DFT in [ReOSe(2-pySe)₃]; see Cargnelutti, Roberta; Lang, Ernesto S.; Piquini, Paulo; Abram, Ulrich (2014). "Synthesis and structure of [ReOSe(2-Se-py)3]: A rhenium(V) complex with selenium(0) as a ligand". Inorganic Chemistry Communications. 45: 48–50. doi:10.1016/j.inoche.2014.04.003. ISSN 1387-7003.

[4] Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 0080379419.

[5] Magnetic susceptibility of the elements and inorganic compounds, in Lide, D. R., ed. (2005). CRC Handbook of Chemistry and Physics (86th ed.). Boca Raton (FL): CRC Press. ISBN 0-8493-0486-5.

[6] Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 0080379419.

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