Period 6 element heavy metal, lead is a neurotoxin that accumulates both in soft tissues and the bones. Lead poisoning has been documented from ancient Rome, ancient Greece, and ancient China. Bismuth is a chemical element with symbol Bi and atomic number 83. Bismuth, a trivalent other metal, chemically resembles arsenic and antimony. Elemental bismuth may occur naturally uncombined, although its sulfide and oxide form important commercial ores. The free element is 86% as dense as lead. It is a brittle metal with a silvery white color when newly made, but often seen in air with a pink tinge owing to the surface
Chemical equation a 2 before O, giving the balanced equation: This equation does not have any coefficients in front of CH and CO, since a coefficient of 1 is dropped. Generally, any chemical equation involving "J" different molecules can be written as: where "R" is the symbol for the "j-th" molecule, and ν is the stoichiometric coefficient for the "j-th" molecule, positive for products, negative for reactants (or vice versa). A properly balanced chemical equation will then obey: where the composition matrix "a" is the number of atoms of element "i" in molecule "j". Any vector which, when operated upon by the