Post-transition metal packing structure. Tin forms Zintl phases such as NaSn, BaSn, KSn and CaSn. It has good corrosion resistance in air on account of forming a thin protective oxide layer. Pure tin has no structural uses. It is used in lead-free solders, and as a hardening agent in alloys of other metals, such as copper, lead, titanium and zinc. Lead is a soft metal (MH 1.5, but hardens close to melting) which, in many cases, is unable to support its own weight. It has a close-packed structure (BCN 12) but an abnormally large inter-atomic distance that has been attributed to partial
Constant phase element Constant phase element A constant phase element is an equivalent electrical circuit component that models the behaviour of a double layer, that is an imperfect capacitor. Constant phase elements are also used in equivalent circuit modelling and data fitting of electrochemical impedance spectroscopy data. A constant phase element also appears currently in modeling the behaviour of the imperfect dielectrics. The generalization in the fields of imperfect electrical resistances, capacitances and inductances leads to the general "Phasance" concept: http://fr.scribd.com/doc/71923015/The-Phasance-Concept The electrical impedance can be calculated: where the CPE admittance is: formula_2 and Q and n (0<n<1) are frequency independent. Q =