Group 12 / IIB; Zinc Group

	All elements of the zinc family have a rather low melting point, mercury (Hg) is the only metal liquid at room temperatures.
		Zinc (Zn; don't mix up with tin), tin (Sn) and Mercury (Hg) have been know in ancien times, tin is needed for making good tin-bronze and zinc for making brass. Zinc is still heavily used for coating iron and steel to make it more or less rust-proof.
		Zinc and tin are not particularly poisonous or dangerous; for mercury (Hg) and cadmium (Cd) the opposite it true. While the use of mercury is more and more restricted (it is still indispensable for fluorescent light), some cadmium compounds like cadmium sulfide (CdS) or cadmium telluride (CdTe) are important semiconductors, in particular for solar cells.
	Table of Basic Data
		Name (German) Zink Zink Cadmium Cadmium Quecksilber Mercury Atomic number 30 48 80 Atomic mass [u] 65,39 112,41 200,59 Melting point [K] 692 594 234,1 Melting point [oC] 419 321 -38,9 Melting point [oF] 786.2 609.8 -38 Boiling point [K] 1181 1040 630 Density [g/cm3] 7,13 8,65 13,55 Ionization energy [eV] 9,4 10,4 10,4 Electronegativitiy 1,7 1,5 1,5 Atomic radius [pm] 138 154 157 Ionic radius [pm] 83 103 112 Oxidation numbers 2 1, 2 1, 2 Lattice typ Transformation temp. [oC] hcp - hcp - r - Lattice constant [Å] (a or c) 2,66 4,95 2,97 5,61 1,57 3,0 Young's - Modul us [GPa] 92,2 50 ? Therm. expansion coefficient a [10-6K-1] ? ? ?
		In case of doubt all numbers are for room temperatures
		fcc = face centered cubic; lattice const. = a bcc = body centered cubic sc = simple cubic hp = simple hexagonal hcp = hexagonal close packed; lattice constants a and c. op = simple orthorhombic, monoclinic, triclinic tp = simple tetragonal dia = diamond structure r = trigonal or rhomboedral trigonal

With frame

Glossary

Periodic Table of the Elements

Bravais Lattices and Crystals

Diamond, and other Carbon Specialities

Lattice and Crystal

Units and Constants

© H. Föll (Iron, Steel and Swords script)