As a bulk metal, cadmium is insoluble in water and is not flammable; however, in its powdered form it may burn and release toxic fumes.

As such configuration strongly resists removal of an electron, mercury behaves similarly to noble gas elements, which form weak bonds and thus easily melting solids.

Those electrons are more easily removed and are shared between the gold atoms forming relatively strong metallic bonds.

Other metals long known to form binary alloys with zinc are aluminium, antimony, bismuth, gold, iron, lead, mercury, silver, tin, magnesium, cobalt, nickel, tellurium and sodium.

Mercury readily combines with aluminium to form a mercury-aluminium amalgam when the two pure metals come into contact.

The elements of group 12 have an oxidation state of +2 in which the ions have the rather stable d10 electronic configuration, with a full sub-shell.

Just as with mercury, the formation of a metal-metal bond results in a diamagnetic compound in which there are no unpaired electrons; thus, making the species very reactive.

Indeed, useful comparison can be made between their properties and the first two members of group 2, beryllium and magnesium, and in earlier short-form periodic table layouts, this relationship is illustrated more clearly.

Both zinc and cadmium can also form octahedral complexes such as the aqua ions [M(H2O)6]2+ which are present in aqueous solutions of salts of these metals.

[36][37] Zinc was distinctly recognized as a metal under the designation of Fasada in the medical Lexicon ascribed to the Hindu king Madanapala (of Taka dynasty) and written about the year 1374.

[44] Experiments on frogs by the Italian doctor Luigi Galvani in 1780 with brass paved the way for the discovery of electrical batteries, galvanization and cathodic protection.

[47] In 1817, cadmium was discovered in Germany as an impurity in zinc carbonate minerals (calamine) by Friedrich Stromeyer and Karl Samuel Leberecht Hermann.

[50][51][52] In 1927, the International Conference on Weights and Measures redefined the meter in terms of a red cadmium spectral line (1 m = 1,553,164.13 wavelengths).

[59] The heaviest known group 12 element, copernicium, was first created on February 9, 1996, at the Gesellschaft für Schwerionenforschung (GSI) in Darmstadt, Germany, by Sigurd Hofmann, Victor Ninov et al.[61] It was then officially named by the International Union of Pure and Applied Chemistry (IUPAC) after Nicolaus Copernicus on February 19, 2010, the 537th anniversary of Copernicus' birth.

Group 12 metals are chalcophiles, meaning the elements have low affinities for oxides and prefer to bond with sulfides.

This association is caused by the geochemical similarity between zinc and cadmium which makes geological separation unlikely.

As a consequence, cadmium is produced mainly as a byproduct from mining, smelting, and refining sulfidic ores of zinc, and, to a lesser degree, lead and copper.

[76] Several other countries are believed to have unrecorded production of mercury from copper electrowinning processes and by recovery from effluents.

[77] Zinc is the fourth most common metal in use, trailing only iron, aluminium, and copper with an annual production of about 10 million tonnes.

Whereas most of the isotopes of copernicium can be synthesized directly this way, some heavier ones have only been observed as decay products of elements with higher atomic numbers.

[87] The first fusion reaction to produce copernicium was performed by GSI in 1996, who reported the detection of two decay chains of copernicium-277 (though one was later retracted, as it had been based on data fabricated by Victor Ninov):[61] Due to the physical similarities which they share, the group 12 elements can be found in many common situations.

Zinc and cadmium are commonly used as anti-corrosion (galvanization) agents[2] as they will attract all local oxidation until they completely corrode.

[92] The relative reactivity of zinc and its ability to attract oxidation to itself makes it an efficient sacrificial anode in cathodic protection (CP).

For example, cathodic protection of a buried pipeline can be achieved by connecting anodes made from zinc to the pipe.

[93] Zinc acts as the anode (negative terminus) by slowly corroding away as it passes electric current to the steel pipeline.

[93] Other widely used alloys that contain zinc include nickel silver, typewriter metal, soft and aluminium solder, and commercial bronze.

[103] Cadmium electroplating, consuming 6% of the global production, can be found in the aircraft industry due to the ability to resist corrosion when applied to steel components.

The group 12 elements have multiple effects on biological organisms as cadmium and mercury are toxic while zinc is required by most plants and animals in trace amounts.

[117] Harmful excessive supplementation may be a problem and should probably not exceed 20 mg/day in healthy people,[118] although the U.S. National Research Council set a Tolerable Upper Intake of 40 mg/day.

[119] Mercury and cadmium are toxic and may cause environmental damage if they enter rivers or rain water.