 |
Selenium |
---|
Pípè | /sᵻˈliːniəm/ (sə-LEE-nee-əm) |
---|
Ìhànsójú | Black, gray, and red allotropes |
---|
Ìwúwo átọ̀mù Ar, std(Se) | 78.971(8)[1] |
---|
Selenium ní orí tábìlì àyè |
---|
|
Nọ́mbà átọ̀mù (Z) | 34 |
---|
Ẹgbẹ́ | group 16 (chalcogens) |
---|
Àyè | àyè 4 |
---|
Àdìpọ̀ | Àdìpọ̀-p |
---|
Ẹ̀ka ẹ́límẹ́ntì | Reactive nonmetal |
---|
Ìtò ẹ̀lẹ́ktrọ́nù | [Ar] 3d10 4s2 4p4 |
---|
Iye ẹ̀lẹ́ktrọ́nù lórí ìpele kọ̀ọ̀kan | 2, 8, 18, 6 |
---|
Àwọn ohun ìní ara |
---|
Ìfarahàn at STP | solid |
---|
Ìgbà ìyọ́ | 494 K (221 °C, 430 °F) |
---|
Ígbà ìhó | 958 K (685 °C, 1265 °F) |
---|
Kíki (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 | 95.48 kJ/mol |
---|
Molar heat capacity | 25.363 J/(mol·K) |
---|
pressure
P (Pa)
|
1
|
10
|
100
|
1 k
|
10 k
|
100 k
|
---|
at T (K)
|
500
|
552
|
617
|
704
|
813
|
958
|
---|
|
Atomic properties |
---|
Oxidation states | −2, −1, +1,[2] +2, +3, +4, +5, +6 Àdàkọ:Infobox element/symbol-to-oxidation-state/comment |
---|
Electronegativity | Pauling scale: 2.55 |
---|
Atomic radius | empirical: 120 pm |
---|
Covalent radius | 120±4 pm |
---|
Van der Waals radius | 190 pm |
---|
Spectral lines of selenium |
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[3] |
---|
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 |
---|
Main isotopes of selenium |
---|
|
Àdàkọ:Category-inline | references |