Silicon by inflammation and scarring in the form of nodular lesions in the upper lobes of the lungs. Silicon Silicon is a chemical element with symbol Si and atomic number 14. It is a hard and brittle crystalline solid with a blue-grey metallic lustre; and it is a tetravalent metalloid and semiconductor. It is a member of group 14 in the periodic table: carbon is above it; and germanium, tin, and lead are below it. It is relatively unreactive. Because of its large chemical affinity for oxygen, it was not until 1823 that Jöns Jakob Berzelius was first able to prepare
CB military symbol or have been, used by the United States: Material Testing Program EA (Edgewood Arsenal) numbers:<br> CB military symbol Chemical, biological (CB) — and sometimes radiological — warfare agents were assigned what is termed a military symbol by the U.S. military until the American chemical and biological weapons programs were terminated (in 1990 and 1969, respectively). Military symbols applied to the CB agent fill, and not to the entire weapon. A chemical or biological weapon designation would be, for example, "Aero-14/B", which could be filled with GB, VX, TGB, or with a biological modification kit – OU, NU, UL, etc. A