Cadmium Atomic Number: 48
Cadmium Symbol: Cd
Cadmium Atomic Weight: 112.411
Cadmium Discovery: Fredrich Stromeyer 1817 (Germany)
Electron Configuration: [Kr] 4d10 5s2
Word Origin: Latin cadmia, Greek kadmeia - ancient name for calamine, zinc carbonate. Cadmium was first discovered by Stromeyer as an impurity in zinc carbonate.
Properties: Cadmium has a melting point of 320.9°C, boiling point of 765°C, spcific gravity of 8.65 (20°C), and a valence of 2. Cadmium is a blue-white metal soft enough to be easily cut with a knife.
Uses: Cadmium is used in alloys with low melting points. It is a component of bearing alloys to given them a low coefficient of friction and resistance to fatigue. Most cadium is used for electroplating. It is also used for many types of solder, for NiCd batteries, and to control atomic fission reactions. Cadmium compounds are used for black and white television phosphors and in the green and blue phosphors for color television tubes. Cadmium salts have wide application. Cadmium sulfide is used as a yellow pigment. Cadmium and its compounds are toxic.
Sources: Cadmium is most commonly found in small quantities associated with zinc ores (e.g., sphalerite ZnS). The mineral greenockite (CdS) is another source of cadmium. Cadmium is obtained as a by-product during treatment of zinc, lead, and copper ores.
Element Classification: Transition Metal
Density (g/cc): 8.65
Melting Point (K): 594.1
Boiling Point (K): 1038
Appearance: soft, malleable, blue-white metal
Atomic Radius (pm): 154
Atomic Volume (cc/mol): 13.1
Covalent Radius (pm): 148
Ionic Radius: 97 (+2e)
Specific Heat (@20°C J/g mol): 0.232
Fusion Heat (kJ/mol): 6.11
Evaporation Heat (kJ/mol): 59.1
Debye Temperature (K): 120.00
Pauling Negativity Number: 1.69
First Ionizing Energy (kJ/mol): 867.2
Oxidation States: 2
Lattice Structure: Hexagonal
Lattice Constant (Å): 2.980
Lattice C/A Ratio: 1.886
References: Los Alamos National Laboratory (2001), Crescent Chemical Company (2001), Lange's Handbook of Chemistry (1952), CRC Handbook of Chemistry & Physics (18th Ed.)
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