Cadmium

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Cadmium,  48Cd
Cadmium-crystal bar.jpg
General properties
Appearance sillery bluish-gray metallic
Staundart atomic wecht (Ar, staundart) 112.414(4)
Cadmium in the periodic cairt
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 Airn Cobalt Nickel Capper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Siller (element) 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 Mercur (element) Thallium Leid (element) 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 Ununtrium Flerovium Ununpentium Livermorium Ununseptium Ununoctium
Zn

Cd

Hg
sillercadmiumindium
Atomic nummer (Z) 48
Group group 12
Period period 5
Element category   transeetion metal
Block d-block
Electron confeeguration [Kr] 4d10 5s2
Electrons per shell
2, 8, 18, 18, 2
Pheesical properties
Phase (at STP) solit
Meltin pynt 594.22 K ​(321.07 °C, ​609.93 °F)
Bylin pynt 1040 K ​(767 °C, ​1413 °F)
Density (near r.t.) 8.65 g/cm3
when liquid (at m.p.) 7.996 g/cm3
Heat o fusion 6.21 kJ/mol
Heat o vapourisation 99.87 kJ/mol
Molar heat capacity 26.020 J/(mol·K)
Vapour pressur
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 530 583 654 745 867 1040
Atomic properties
Oxidation states 2, 1 (mildly basic oxide)
Electronegativity Pauling scale: 1.69
Atomic radius empirical: 151 pm
Covalent radius 144±9 pm
Van der Waals radius 158 pm
Color lines in a spectral range
Miscellanea
Crestal structur hexagonal close-packed (hcp)
Hexagonal close packed creestal structur for cadmium
Speed o soond thin rod 2310 m/s (at 20 °C)
Thermal expansion 30.8 µm/(m·K) (at 25 °C)
Thermal conductivity 96.6 W/(m·K)
Electrical resistivity (22 °C) 72.7 n Ω·m
Magnetic orderin diamagnetic[1]
Young's modulus 50 GPa
Shear modulus 19 GPa
Bouk modulus 42 GPa
Poisson ratio 0.30
Mohs haurdness 2.0
Brinell haurdness 203 MPa
CAS Nummer 7440-43-9
History
Diskivery Karl Samuel Leberecht Hermann an Friedrich Stromeyer (1817)
First isolation Karl Samuel Leberecht Hermann an Friedrich Stromeyer (1817)
Named bi Friedrich Stromeyer (1817)
Main isotopes o cadmium
Iso­tope Abun­dance Hauf-life (t1/2) Decay mode Pro­duct
106Cd 1.25% >4.1×1020 y (β+β+) 106Pd
107Cd syn 6.5 h ε 107Ag
108Cd 0.89% >4.1×1017 y (β+β+) 108Pd
109Cd syn 462.6 d ε 109Ag
110Cd 12.49% - (SF)
111Cd 12.8% - (SF)
112Cd 24.13% - (SF)
113Cd 12.22% 7.7×1015 y β 113In
113mCd syn 14.1 y β 0.580 113In
IT 0.264 113Cd
114Cd 28.73% >6.4×1018 y (ββ) 114Sn
115Cd syn 53.46 h β 115In
116Cd 7.49% 3.1×1019 y ββ 116Sn
Decay modes in parentheses are predictit, but hae nae yet been observed
| references | in Wikidata

Cadmium is a chemical element wi the seembol Cd an atomic nummer 48. This saft, bluish-white metal is chemically seemilar tae the twa ither stable metals in group 12, zinc an mercur. Lik zinc, it prefers oxidation state +2 in maist o its compoonds an lik mercur it shaws a law meltin pynt compared tae transeetion metals. Cadmium an its congeners are nae always considered transeetion metals, in that thay dae nae hae pairtly filled d or f electron shells in the elemental or common oxidation states. The average concentration o cadmium in the Yird's crust is atween 0.1 an 0.5 pairts per million (ppm). It wis discovered in 1817 simultaneously bi Stromeyer an Hermann, baith in Germany, as an impurity in zinc carbonate.

References[eedit | eedit soorce]

  1. Lide, D. R., ed. (2000). "Magnetic susceptibility of the elements and inorganic compounds". [[CRC Handbook of Chemistry and Physics]] (PDF) (81st ed.). CRC Press. ISBN 978-0-8493-0481-1.  URL–wikilink conflict (help)