Chemicool

Ca

20

40.08
Calcium
General | States | Energies | Oxidation & Electrons |Appearance & Characteristics
Reactions | Other Forms |Radius | Conductivity | Abundance
Encyclopedia Britannica articles

General
Name Calcium Symbol Ca
atomic number 20 Atomic weight 40.08
Density @ 293 K 1.55 g/cm3 Atomic volume 29.9 cm3/mol
Group Alkali Earth discovered 1808

States
state (s, l, g) s
melting point 1112.2 K boiling point 1767 K
Heat of fusion 8.540 kJ/mol Heat of vaporization 153.60 kJ/mol
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Energies
1st ionization energy 589.8 kJ/mole electronegativity 1
2nd ionization energy 1145.4 kJ/mole electron affinity kJ/mole
3rd ionization energy 4911.8 kJ/mole Specific heat 0.63 J/gK
heat atomization 178 kJ/mole atoms

Oxidation & Electrons
Shells 2,8,8,2 electron configuration [Ar] 4s2
minimum oxidation number 0 maximum oxidation number 2
min. common oxidation no. 0 max. common oxidation no. 2
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Appearance & Characteristics
structure hcp: hexagonal close pkd color silvery-white
uses lime, cement toxicity
hardness 1.5 mohs characteristics burns brightly

Reactions
reaction with air vigorous, = CaO, Ca3N2 reaction with 6M HCl vigorous, = H2, CaCl2
reaction with 6M HCl vigorous, = H2, CaCl2 reaction with 15M HNO3 vigorous, = H2, Ca(NO3)2
reaction with 6M NaOH none
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Other Forms
number of isotopes 6 hydride(s) CaH2
oxide(s) CaO chloride(s) CaCl2

Radius
ionic radius (2- ion) pm ionic radius (1- ion) pm
atomic radius 197 pm ionic radius (1+ ion) pm
ionic radius (2+ ion) 114 pm ionic radius (3+ ion) pm
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Conductivity
thermal conductivity 201 J/m-sec-deg electrical conductivity 255.754 1/mohm-cm
polarizability 22.8 A^3

Abundance
source Calcite (oxide) rel. abund. solar system 4.786 log
abundance earth's crust 4.65 log cost, pure 11 $/100g
cost, bulk $/100g
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