Barium avoid a potentially vigorous chemical reaction, barium metal is kept in an argon atmosphere or under mineral oils. Contact with air is dangerous and may cause ignition. Moisture, friction, heat, sparks, flames, shocks, static electricity, and exposure to oxidizers and acids should be avoided. Anything that may contact with barium should be electrically grounded. Anyone who works with the metal should wear pre-cleaned non-sparking shoes, flame-resistant rubber clothes, rubber gloves, apron, goggles, and a gas mask. Smoking in the working area is forbidden. Thorough washing is required after handling barium. Barium Barium is a chemical element with symbol Ba and
Sterling silver Netherlands, the Baltic, Germany, and even deeper regions of central Europe." The sterling alloy originated in continental Europe and was being used for commerce as early as the 12th century in the area that is now northern Germany. In England the composition of sterling silver was subject to official assay at some date before 1158, during the reign of Henry II, but its purity was probably regulated from centuries earlier, in Saxon times. A piece of sterling silver dating from Henry II's reign was used as a standard in the Trial of the Pyx until it was deposited at the