Group 12 element have zinc in its active site. In 1817, cadmium was discovered in Germany as an impurity in zinc carbonate minerals (calamine) by Friedrich Stromeyer and Karl Samuel Leberecht Hermann. It was named after the Latin "cadmia" for "calamine", a cadmium-bearing mixture of minerals, which was in turn named after the Greek mythological character, Κάδμος Cadmus, the founder of Thebes. Stromeyer eventually isolated cadmium metal by roasting and reduction of the sulfide. 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). This definition has since
Metallic bonding its boiling point is not far from that of copper. Molten gallium is therefore a very nonvolatile liquid thanks to its strong metallic bonding. The strong bonding of metals in the liquid form demonstrates that the energy of a metallic bond is not a strong function of the direction of the metallic bond; this lack of bond directionality is a direct consequence of electron delocalization, and is best understood in contrast to the directional bonding of covalent bonds. The energy of a metallic bond is thus mostly a function of the number of electrons which surround the metallic atom, as