Lát'ọwọ́ Wikipedia, ìwé ìmọ̀ ọ̀fẹ́
| Selenium |
|
34Se
|
|
|
| Ìhànsójú |
Black, gray, and red allotropes
 |
| Àwọn ìdámọ́ wíwọ́pọ̀ |
| Orúkọ, àmì-ìdámọ́, nọ́mbà |
selenium, Se, 34 |
| Ẹ̀ka ẹ́límẹ̀nti |
nonmetal |
| Ẹgbẹ́, àsìkò, àdìpò |
16, 4, p |
| Ìwúwo átọ́mù |
78.96 |
| Ìtòléra ẹ̀lẹ́ktrónì |
[Ar] 4s2 3d10 4p4
2, 8, 18, 6 |
| Physical properties |
| Phase |
solid |
| Density (near r.t.) |
(gray) 4.81 g·cm−3 |
| Density (near r.t.) |
(alpha) 4.39 g·cm−3 |
| Density (near r.t.) |
(vitreous) 4.28 g·cm−3 |
| Liquid density at m.p. |
3.99 g·cm−3 |
| Melting point |
494 K, 221 °C, 430 °F |
| Boiling point |
958 K, 685 °C, 1265 °F |
| Critical point |
1766 K, 27.2 MPa |
| Heat of fusion |
(gray) 6.69 kJ·mol−1 |
| Heat of vaporization |
95.48 kJ·mol−1 |
| Molar heat capacity |
25.363 J·mol−1·K−1 |
| Vapor 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 |
6, 4, 2, 1,[1] -2
(strongly acidic oxide) |
| Electronegativity |
2.55 (Pauling scale) |
| Ionization energies |
1st: 941.0 kJ·mol−1 |
| 2nd: 2045 kJ·mol−1 |
| 3rd: 2973.7 kJ·mol−1 |
| Atomic radius |
120 pm |
| Covalent radius |
120±4 pm |
| Van der Waals radius |
190 pm |
| Miscellanea |
| Crystal structure |
hexagonal
|
| Magnetic ordering |
diamagnetic[2] |
| Thermal conductivity |
(amorphous) 0.519 W·m−1·K−1 |
| Thermal expansion |
(25 °C) (amorphous) 37 µm·m−1·K−1 |
| Speed of sound (thin rod) |
(20 °C) 3350 m·s−1 |
| 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 registry number |
7782-49-2 |
| Àwọn ísótòpù dídúró jùlọ |
| Main article: Àwọn ísótòpù selenium |
|
|
|
· r |
