Kalsium

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kalium ← Kalsium → skandium

Mg
↑
Ca
↓
Sr

tabel periodik

General

Ngaran, Lambang, Nomer

Kalsium, Ca, 20

Dérét kimia

logam alkali taneuh

Golongan, Periode, Blok

2, 4, s

Kelir

bodas semu pérak

Massa atom

40.078(4) g/mol

Konfigurasi éléktron

[Ar] 4s²

Éléktron per cangkang

2, 8, 8, 2

Pasipatan fisik

Fase

padet

Dénsitas (dina h.r.)

1.55 g/cm³

Dénsitas cairan dina t.l.

1.378 g/cm³

Titik lééh

1115 K
(842 °C, 1548 °F)

Titik golak

1757 K
(1484 °C, 2703 °F)

Panas fusi

8.54 kJ/mol

Panas uap

154.7 kJ/mol

Kapasitas panas

(25 °C) 25.929 J/(mol·K)

Tekenan uap
P/Pa	1	10	100	1 k	10 k	100 k
at T/K	864	956	1071	1227	1443	1755

Pasipatan atom

Struktur kristal

kubus museur beungeut

Wujud oksidasi

2
(oksida basa kuat)

Éléktronégativitas

1.00 (skala Pauling)

Énergi ionisasi
(lianna)

1st: 589.8 kJ/mol

2nd: 1145.4 kJ/mol

3rd: 4912.4 kJ/mol

Radius atom

180 pm

Radius atom (calc.)

194 pm

Radius kovalén

174 pm

Unak-anik

Susunan magnétik

paramagnétik

Résistivitas listrik

(20 °C) 33.6 nΩ·m

Konduktivitas panas

(300 K) 201 W/(m·K)

Ékspansi panas

(25 °C) 22.3 µm/(m·K)

Laju sora (pelat ipis)

(20 °C) 3810 m/s

Modulus Young

20 GPa

Modulus Shear

7.4 GPa

Modulus Bulk

17 GPa

Nisbah Poisson

0.31

Kateuasan Mohs

1.75

Kateuasan Brinell

167 MPa

Nomer régister CAS

7440-70-2

Isotop penting

Artikel utama: Isotop kalsium
iso	NA	umur satengah	DM	DE (MeV)	DP
⁴⁰Ca	96.941%	Ca stabil jeung 20 neutron
⁴¹Ca	syn	1.03×10⁵ y	ε	-	⁴¹K
⁴²Ca	0.647%	Ca stabil jeung 22 neutron
⁴³Ca	0.135%	Ca stabil jeung 23 neutron
⁴⁴Ca	2.086%	Ca stabil jeung 24 neutron
⁴⁵Ca	syn	162.7 d	β^-	0.258	⁴⁵Sc
⁴⁶Ca	0.004%	>2.8×10¹⁵ y	β^-β^-	?	⁴⁶Ti
⁴⁷Ca	syn	4.536 d	β^-	0.694, 1.99	⁴⁷Sc
⁴⁷Ca	syn	4.536 d	γ	1.297	-
⁴⁸Ca	0.187%	>4×10¹⁹ y	β^-β^-	?	⁴⁸Ti

Rujukan

Kalsium ngarupakeun unsur kimiawi na tabel periodik nu lambangna Ca sarta wilangan atom 20. Kalsium is a soft grey alkaline earth metal nu dipaké salaku agén pangréduksi na ékstraksi thorium, zirconium, jeung uranium. Unsur ieu ogé mangrupa unsur kalima nu paling ngaleuyah na kulit Marcapada. Penting pikeun organisme hirup, utamana dina fisiologi sél.

[édit] Ciri penting

Kalsium téh unsur teuas nu dimurnikeun ku jalan éléktrolisis kalsium fluorida, nu mun kaduruk seuneuna konéng-héjo, sarta ngabentuk nitrida bodas mun keuna ku udara. Dina cai, kalsium bakal jadi kalsium hidroksida.

[édit] Larapan

Kalsium téh salah sahiji komponén penting katuangan, kurang asupanana bisa ngabalukarkeun gangguan formasi tulang jeung huntu. Tapi konsumsi kalsium gé ulah nepi ka loba teuing, sabab bisa ngabalukarkeun batu ginjal. Kalsium bisa diserep ku peujit mun aya Vitamin D.

Pikeun leuwih lengkep ngeunaan Ca dina kahirupan, mangga aos kalsium dina biologi.

[édit] History

(Latin calx, lime) Lime was prepared and used by the Romans as early as the 1st century, but calcium was not discovered until 1808. After learning that Berzelius and Pontin prepared calcium amalgam by electrolyzing lime in mercury, Sir Humphry Davy was able to isolate the impure metal.

[édit] Occurrence

Calcium is the fifth most abundant element in the earth's crust (forming more than 3%) and is an essential part of leaves, bones, teeth, and shells. Due to its chemical reactivity with air and water, calcium is never found in nature unbound to other elements, except in living organisms where Ca²⁺ plays a key role in cell physiology. This metallic element is found in quantity in limestone, gypsum, and fluorite. Apatite is the fluorophosphate or chlorophosphate of calcium. Electrolysis of molten calcium chloride (CaCl₂) can be used to isolate pure calcium.
Isolation (* follow):
cathode: Ca²⁺* + 2e^- --> Ca
anode: Cl^-* --> ½Cl₂ (gas) + e^-

[édit] Compounds

Quicklime (CaO) is used in many chemical refinery processes and is made by heating and carefully adding water to limestone. When CaO is mixed with sand it hardens into a mortar and is turned into plaster by carbon dioxide uptake. Mixed with other compounds, CaO forms an important part of Portland cement.

When water percolates through limestone or other soluble carbonate rocks, it partially disolves part of the rock and causes cave formation and characteristic stalactites and stalagmites and also forms hard water. Other important calcium compounds are nitrate, sulfide, chloride, carbide, cyanamide, and hypochlorite.

[édit] Isotop

Kalsium boga genep isotop stabil, dua di antarana aya di alam: Ca-40 stabil jeung Ca-41 radioaktif nu umur-satengahna = 103.000 taun. 97% unsur ieu aya dina wujud Ca-40. Ca-40 téh turunan tina luruhna K-40, nu ogé ngahasilkeun Ar-40.

Baca ogé: gangguan métabolisme kalsium

[édit] Tumbu kaluar

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