Barium
Barium (Ba) is a chemical element with the atomic number 56. It is a soft, silvery-white alkaline earth metal that is never found in nature in its pure form due to its high reactivity with air. Barium is classified in Group 2 (alkaline earth metals) of the periodic table.
Properties:
- Symbol: Ba
- Atomic Number: 56
- Atomic Weight: 137.33
- Appearance: Silvery-white (oxidizes to grayish-white upon exposure to air)
- State at Room Temperature: Solid
- Density: 3.51 g/cm³
- Melting Point: 727 °C (1341 °F)
- Boiling Point: 1897 °C (3447 °F)
- Electronegativity: 0.89 (Pauling scale)
- Reactivity: Highly reactive, especially with water and oxygen.
- Common Oxidation States: +2
Occurrence and Production:
Barium is primarily found in the minerals barite (barium sulfate, BaSO₄) and witherite (barium carbonate, BaCO₃). Commercially, barium is produced by electrolysis of molten barium chloride (BaCl₂). It can also be produced by reducing barium oxide (BaO) with aluminum at high temperatures.
Uses:
Barium and its compounds have a variety of applications, including:
- Medical: Barium sulfate is used as a radiocontrast agent for X-ray imaging of the gastrointestinal tract. It is relatively insoluble and not absorbed by the body, making it safe for this application.
- Industry: Barium carbonate is used in the manufacture of rat poison, bricks, ceramic glazes, and optical glass.
- Drilling Fluids: Barite (barium sulfate) is used as a weighting agent in drilling fluids for oil and gas wells. Its high density helps to control pressure and prevent blowouts.
- Fireworks: Barium compounds are used to produce green colors in fireworks.
- Electronics: Barium titanate (BaTiO₃) is used in capacitors and other electronic components.
Safety:
Many barium compounds are toxic. Soluble barium compounds are particularly dangerous and can cause muscle paralysis, heart problems, and other health issues. Barium sulfate is generally considered safe for medical use because it is insoluble and poorly absorbed. However, proper handling and disposal of barium compounds are essential to minimize health risks.