Kalsiyum

Kalsium,  ₂₀Ca

General properties
Wujud	putih asemu pérak
Bobot atom standar (Ar, standard)	7001400780000000000♠40.078(4)
Kalsium in the periodic table
Hydrogen Helium Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson Mg ↑ Ca ↓ Sr kalium ← kalsium → skandium
Atomic number (Z)	20
Group	group 2 (alkaline earth metals)
Period	period 4
Blok	s-block
Konfigurasi èlèktron	[Ar] 4s2
Electrons per shell	2, 8, 8, 2
Sipat angga
Phase at STP	solid
Melting point	1115 K ​(842 °C, ​1548 °F)
Boiling point	1757 K ​(1484 °C, ​2703 °F)
Density (near r.t.)	1,55 g/cm3
when liquid (at m.p.)	1,378 g/cm3
Heat of fusion	8,54 kJ/mol
Heat of vaporization	154,7 kJ/mol
Molar heat capacity	25,929 J/(mol·K)
Vapor pressure P (Pa) 1 10 100 1 k 10 k 100 k at T (K) 864 956 1071 1227 1443 1755
Atomic properties
Oxidation states	2 ​oksida basa kuwat
Electronegativity	Pauling scale: 1,00
Ionization energies	(more)
Atomic radius	empirical: 180 pm calculated: 194 pm
Covalent radius	174 pm
Spectral lines
Miscellanea
Crystal structure	​kubik mawa punjer muka Kubik mawa punjer muka crystal structure for kalsium
Speed of sound thin rod	3810 m/s (at 20 °C)
Thermal expansion	22,3 µm/(m·K) (at 25 °C)
Thermal conductivity	201 W/(m·K)
Electrical resistivity	33,6 n Ω·m (at 20 °C)
Magnetic ordering	paramagnetik
Young's modulus	20 GPa
Shear modulus	7,4 GPa
Bulk modulus	17 GPa
Poisson ratio	0,31
Mohs hardness	1,75
Brinell hardness	167 MPa
CAS Number	7440-70-2
Main isotopes of kalsium
Iso­tope Abun­dance Half-life (t1/2) Decay mode Pro­duct 40Ca 96,941% Ca stabil kanthi 20 neutron 41Ca syn 1,03×105 taun ε - 41K 42Ca 0,647% Ca stabil kanthi 22 neutron 43Ca 0,135% Ca stabil kanthi 23 neutron 44Ca 2,086% Ca stabil kanthi 24 neutron 45Ca syn 162,7 hari β- 0,258 45Sc 46Ca 0,004% >2,8×1015 taun β-β- ? 46Ti 47Ca syn 4,536 hari β- 0,694, 1,99 47Sc γ 1.297 - 48Ca 0,187% >4×1019 taun β-β- ? 48Ti

Kalsium (calcium (Ca)), iku unsur élemèn kimia, salah sawijiné logam alkalin bumi saka golongan 2 (IIa) ing tabel periodik. Kalsium iku unsur logam kang akèh dhéwé sajeroning awak manungsa lan élemèn kalima kang akèh dhéwé ing kerak Bumi.

Kalsium lan manungsa

Kalsium yaiku nutrisi kanggo balung. Kira-kira 99% kalsium ana ing njero jaringan keras yaiku balung lan untu. 1% kalsium ana ing getih, lan jaringan lunak. tanpa kalsium kang 1% iki, otot ngalami gangguan kontraksi, getih angèl mbeku, tranmisi saraf ana masalah, lan sapituruté. kanggé njangkepi 1% kabetahan iki, awak njupuk panganan kang dipangan saka balung. Upama panganan kang dipangan ora cukup, mangka dijupuk saka balung. saé ngga balung bisa diarani cadangan kalsium. Upama kadadéan iki selang wektuné suwé, mangka balung bakal ngalami keropos balung. Kalsium zat kang dibutuhaké saka bayi nganti tuwa. Cacahé kabutuhan kalsium dibedakaké miturut jinis kelamin lan umur. Miturut dhokter gizi, kabutuhan wong-wong Indonésia iku antarané 500-800 mg/ dina. Wektu wong kang wis tuwa lan wadon ménopause disaranke ngombé asupan kalsium 1000 mg /dina.