Barium green color. Barium sulfate is used as an insoluble additive to oil well drilling fluid, as well as in a purer form, as X-ray radiocontrast agents for imaging the human gastrointestinal tract. The soluble barium ion and soluble compounds are poisonous, and have been used as rodenticides. Barium is a soft, silvery-white metal, with a slight golden shade when ultrapure. The silvery-white color of barium metal rapidly vanishes upon oxidation in air yielding a dark gray oxide layer. Barium has a medium specific weight and good electrical conductivity. Ultrapure barium is very difficult to prepare, and therefore many properties of
Sodium chlorate herbicides in aqueous solution is possible to some extent, so long as they are not susceptible to oxidation. The sale of sodium chlorate as a weedkiller was banned in the European Union in 2009, with existing stocks to be used within the following year. Chemical oxygen generators, such as those in commercial aircraft, provide emergency oxygen to passengers to protect them from drops in cabin pressure. Oxygen is generated by high-temperature decomposition of sodium chlorate: Heat required for this reaction is generated by oxidation of a small amount of iron powder mixed with the sodium chlorate, and the reaction consumes