Thursday, August 30, 2007

Krom www.tool-tool.com

Bewise Inc. www.tool-tool.com Reference source from the internet.
24 Vanadium ← Krom → Mangan

↑
Cr
↓
Mo
Krom i periodesystemet
Generelle eigenskapar
Namn, kjemisk symbol,
atomnummer
Krom, Cr, 24
Kjemisk serie Transisjonsmetall
Gruppe, periode, blokk 6, 4, d
Tettleik, hardleik 7140 kg/m3, 8,5 (ikkje SI)
Utsjånad Sølvaktig
Krom
Atomeigenskapar
Atommasse 51,9961 u (ikkje SI)
Atomradius (berekna) 140 (166) pm
Kovalent radius 127 pm
Ioneradius 62 pm (ladning: +3)
van der Waals radius (?) pm
Elektronkonfigurasjon [Ar]3d54s1
Elektron per energinivå 2, 8, 13, 1
Oksidasjonstrinn (oksid) +2, +3, +6 (sterk syre)
Krystallstruktur Kubisk romsentrert
Fysiske eigenskapar
Tilstandsform Fast stoff
Smeltepunkt 2130 K (1857°C)
Kokepunkt 2945 K (2672°C)
Molart volum 7,23 cm3/mol
Fordampingsvarme 344,3 kJ/mol
Smeltevarme 16,9 kJ/mol
Damptrykk 990 Pa ved 2130 K
Ljodfart 5940 m/s ved 20°C
Diverse eigenskapar
Elektronegativitet 1,66 (Paulings skala)
Spesifikk varmekapasitet 450 J/(kg·K)
Elektrisk konduktivitet 7,74 MS/m
Termisk konduktivitet 116 W/(m·K)
Ioniseringspotensial 659 kJ/mol
1598 kJ/mol
2993 kJ/mol
4740 kJ/mol
6690 kJ/mol
8744 kJ/mol
15550 kJ/mol
Mest stabile isotopar
Iso-
top
Naturleg
førekomst
Halverings-
tid
(ikkje SI)
NM NE MeV
(ikkje SI)
NP
50Cr (kunstig) >1,8·1017 år 2·ε (?) 50Ti
51Cr (kunstig) 27,7025 d ε 0,753 51V
52Cr 83,789% (stabilt)
53Cr 9,501% (stabilt)
54Cr 2,365% (stabilt)
SI-einingar og STP er brukt unntatt der det er avmerka
Krom er eit metallisk grunnstoff med kjemisk symbol Cr og atomnummer 24. Det er eit transisjonsmetall


BW Bewise Inc. Willy Chen willy@tool-tool.com bw@tool-tool.com www.tool-tool.com skype:willy_chen_bw mobile:0937-618-190 Head &Administration Office No.13,Shiang Shang 2nd St., West Chiu Taichung,Taiwan 40356 TEL:+886 4 24710048 / FAX:+886 4 2471 4839 N.Branch 5F,No.460,Fu Shin North Rd.,Taipei,Taiwan S.Branch No.24,Sec.1,Chia Pu East Rd.,Taipao City,Chiayi Hsien,Taiwan

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Bewise Inc. www.tool-tool.com

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