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
Alkali-metal thermal to electric converter this technology into general residential and commercial cogeneration schemes, although costs per kilowatt-hour would have to drop substantially from current projections. Alkali-metal thermal to electric converter The alkali-metal thermal-to-electric converter (AMTEC), originally called the sodium heat engine (SHE) was invented by Joseph T. Kummer and Neill Weber at Ford in 1966, and is described in US Patents , , and . It is a thermally regenerative electrochemical device for the direct conversion of heat to electrical energy. It is characterized by high potential efficiencies and no moving parts except the working fluid, which make it a candidate for space power