Selenium

Selenium sī 1 ê hoà-ha̍k goân-sò͘. I ê goân-chú-hoan sī 34, hoà-ha̍k hû-hō sī Se.

Selenium,  ₃₄Se

Ki-pún sèng-chit
Miâ, hû-hō	selenium, Se
Gōa-hêng	black, red, and gray (not pictured) allotropes
Selenium tī chiu-kî-piáu lāi ê ūi-tì
S ↑ Se ↓ Te phi-sò͘ ← selenium → chhàu-sò͘
Goân-chú-hoan	34
Goân-chú-liōng (±)	78.971(8)
Goân-sò͘ lūi-pia̍t	to-goân-chú hui-kim-sio̍k sometimes considered a metalloid
Cho̍k, hun-khu	16 cho̍k, p khu
Chiu-kî	tē 4 chiu-kî
Tiān-chú pâi-lia̍t	[Ar] 3d10 4s2 4p4
per shell	2, 8, 18, 6
Bu̍t-lí sèng-chit
Siòng	solid
Iûⁿ-tiám	494 K ​(221 °C, ​430 °F)
Hut-tiám	958 K ​(685 °C, ​1265 °F)
Bi̍t-tō͘  (sek-un)	gray: 4.81 g·cm−3 alpha: 4.39 g·cm−3 vitreous: 4.28 g·cm−3
3.99 g·cm−3
Lîm-kài-tiám	1766 K, 27.2 MPa
Iûⁿ-hoà-jia̍t	gray: 6.69 kJ·mol−1
Cheng-hoat-jia̍t	95.48 kJ·mol−1
Jia̍t-iông-liōng	25.363 J·mol−1·K−1
cheng-khì-ap P (Pa) 1 10 100 1 k 10 k 100 k tī T (K) 500 552 617 704 813 958
Goân-chú sèng-chit
Sng-hòa-sò͘	6, 5, 4, 3, 2, 1, −1, −2 ​(a strongly acidic oxide)
Tiān-hū-tō͘	Pauling scale: 2.55
Tiān-lī-lêng	1st: 941.0 kJ·mol−1 2nd: 2045 kJ·mol−1 3rd: 2973.7 kJ·mol−1
Goân-chú pòaⁿ-kèng	empirical: 120 pm
Kiōng-kè pòaⁿ-kèng	120±4 pm
Van der Waals pòaⁿ-kèng	190 pm
Cha̍p-lio̍k
Chiⁿ-thé kò͘-chō	​hexagonal
Siaⁿ-sok (sòe kùn-á)	3350 m·s−1 (at 20 °C)
Jia̍t-phòng-tiòng	amorphous: 37 µm·m−1·K−1 (at 25 °C)
Jia̍t-thoân-tō-lu̍t	amorphous: 0.519 W·m−1·K−1
Chû-sèng	diamagnetic
Young hē-sò͘	10 GPa
Shear hē-sò͘	3.7 GPa
Bulk hē-sò͘	8.3 GPa
Poisson pí	0.33
Mohs ngē-tō͘	2.0
Brinell ngē-tō͘	736 MPa
CAS teng-kì pian-hō	7782-49-2
Le̍k-sú
Hō-miâ	after Selene, Greek goddess of the moon
Hoat-hiān kap siōng chá ê tông-ūi-sò͘	Jöns Jakob Berzelius and Johann Gottlieb Gahn (1817)
Chòe ún-tēng ê tông-ūi-sò͘
Chú bûn-chiong: selenium ê tông-ūi-sò͘
iso NA half-life DM DE (MeV) DP 72Se syn 8.4 d ε – 72As γ 0.046 – 74Se 0.87% – (β+β+) 1.2094 74Ge 75Se syn 119.779 d ε – 75As γ 0.264, 0.136, 0.279 – 76Se 9.36% 76Se is stable with 42 neutrons 77Se 7.63% 77Se is stable with 43 neutrons 78Se 23.78% 78Se is stable with 44 neutrons 79Se trace 3.27×105 y β− 0.151 79Br 80Se 49.61% – (β−β−) 0.1339 80Kr 82Se 8.73% 1.08×1020 y β−β− 2.995 82Kr
Decay modes in parentheses are predicted, but have not yet been observed