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
Electrical length of "(2N+1)λ"/2. The electrical length of an antenna element is, in general, different from its physical length For example, increasing the diameter of the conductor, or the presence of nearby metal objects, will decrease the velocity of the waves in the element, increasing the electrical length. An antenna which is shorter than its resonant length is described as ""electrically short"" , and exhibits capacitive reactance. Similarly, an antenna which is longer than its resonant length is described as ""electrically long"" and exhibits inductive reactance. An antenna's effective electrical length can be changed without changing its physical length by adding reactance,