Cadmium Facts

Chemical & Physical Properties of Cadmium

Science

By

Anne Marie Helmenstine, Ph.D.

Updated on July 03, 2019

Cadmium Symbol

Cd

Cadmium Atomic Weight

112.411

Cadmium Discovery

Fredrich Stromeyer 1817 (Germany)

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

admium 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

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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