Calcium

Symbol	Ca
Atomnummer	20
Gruppe	2 (Jordalkalimetaller)
Periode	4
Blok	d
Klassifikation	Jordalkalimetal

Udseende	-
Farve	Sølv

Antal protoner	20 p+
Antal neutroner	20 n0
Antal elektroner	20 e-

Fra Wikipedia, den gratis encyklopædiCalcium (af calcis; det latinske ord for kalk) er det 20. grundstof i det periodiske system, og har det kemiske symbol Ca: Under normale temperatur- og trykforhold optræder dette jordalkalimetal som et gråligt metal der er blødere end bly.

Fase ved STP	Fast
Massefylde	1.55 g/cm3
Atommasse	40.0784 u

Smeltepunkt	1115 K 841.85 °C 1547.33 °F
Kogepunkt	1757 K 1483.85 °C 2702.93 °F
Fordampningsvarme	154.67 kJ/mol

Elektronegativitet (Pauling Scale)	1
Elektronaffinitet	2.37 kJ/mol
Oxidationstrin	+1, +2 (a strongly basic oxide)
Ioniseringsenergier	589.8 kJ/mol 1145.4 kJ/mol 4912.4 kJ/mol 6491 kJ/mol 8153 kJ/mol 10496 kJ/mol 12270 kJ/mol 14206 kJ/mol 18191 kJ/mol 20385 kJ/mol 57110 kJ/mol 63410 kJ/mol 70110 kJ/mol 78890 kJ/mol 86310 kJ/mol 94000 kJ/mol 104900 kJ/mol 111711 kJ/mol 494850 kJ/mol 527762 kJ/mol

Elektronkonfiguration Kortfattet konfiguration	[Ar] 4s2
Elektronkonfiguration Fuld konfiguration	1s2 2s2 2p6 3s2 3p6 4s2
Elektronkonfigurationsdiagram	1s2 2s2 2p6 3s2 3p6 4s2
Elektroner pr. Skal	2, 8, 8, 2
Valenselektroner	2
Valency-elektroner	2
Bohrs atommodel	Figur: Skaldiagram af Calcium (Ca) atom.
Orbital diagram	1s 2s 2p 3s 3p 4s

Opdagelse og første isolation

Humphry Davy (1808)

Opdagelse af calcium Calcium compounds were known for millennia, although their chemical makeup was not understood until the 17th century. Lime as a building material and as plaster for statues was used as far back as around 7000 BC. Vitruvius, a Roman architect, noted that the lime that resulted was lighter than the original limestone, attributing this to the boiling of the water. In 1755, Joseph Black proved that this was due to the loss of carbon dioxide, which as a gas had not been recognised by the ancient Romans. In 1789, Antoine Lavoisier suspected that lime might be an oxide of a fundamental chemical element. Calcium, along with its congeners magnesium, strontium, and barium, was first isolated by Humphry Davy in 1808. Following the work of Jöns Jakob Berzelius and Magnus Martin af Pontin on electrolysis.

Original word	calx
Language of origin	Latin
Name source	Mineral
Meaning	“Lime”
Naming The name is derived from the Latin word 'calx' meaning lime, which was obtained from heating limestone.

CAS Number	7440-70-2
ChemSpider ID	4573905
EC number	231-179-5
PubChem CID Number	5460341