Chemistry (Wikipedia)
Chemistry is the scientific study of the properties and behavior of matter. It is a physical science within the natural sciences that studies the chemical elements that make up matter and compounds made of atoms, molecules and ions: their composition, structure, properties, behavior and the changes they undergo during reactions with other substances. Chemistry also addresses the nature of chemical bonds in chemical compounds.- Lead is a chemical element; it has symbol Pb (from Latin plumbum) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cut, lead is a shiny gray with a hint of blue. It tarnishes to a dull gray color when exposed to air. Lead has the highest atomic number of any stable element and three of its isotopes are endpoints of major nuclear decay chains of heavier elements.
- Moganite (Wikipedia)
Moganite is an oxide mineral with the chemical formula SiO2 (silicon dioxide) that was discovered in 1976. It was initially described as a new form of silica from specimens found in the Barranco de Medio Almud, in the municipality of Mogán on the island of Gran Canaria, in the Canary Islands (Spain), receiving in a later work the name derived from this locality. In 1994 the International Mineralogical Association decided to disapprove it as a valid mineral, since it was considered indistinguishable from quartz. Subsequent studies allowed the IMA to rectify it in 1999, accepting it as a mineral species. It has the same chemical composition as quartz, but a different crystal structure.