Characteristics: Silver-white, somewhat malleable metal. Extremely reactive; reacts readily with water, ammonia, halogens, oxygen, and most acids. Gives green color in flame. Extrudable and machinable.
Derivation: Reduction of barium oxide with Barium or silicon in a vacuum at high temperature.
Hazard: Toxic. Flammable (pyrophoric) at room temperature in powder form; store under inert gas, petroleum, or other oxygen-free liquid. When heated to about 200 oC in hydrogen, barium reacts violently, forming BaH2. Tolerance for all soluble barium compounds is 0.5 mg/m3 in air (as Ba).