Ba
137.330Barium
Baryum
Barium is an alkaline earth metal with atomic number 56. Its insoluble sulfate is used as an X-ray contrast material, while barium compounds are important in drilling mud, green fireworks, barium titanate ceramics and sulfate testing.
56
137.33 g/mol
[Xe] 6s²
2 | 8 | 18 | 18 | 8 | 2
0.89
3.51 g/cm³
726.9 °C
1844.8 °C
Humphry Davy
Carl Wilhelm Scheele identified barium minerals as containing a distinct substance in 1774, and Humphry Davy isolated metallic barium by electrolysis in 1808. The name comes from Greek barys, meaning heavy.
Barium-130
Natural abundance: About 0.1%. Rare isotope studied in double beta decay context.Barium-132
Natural abundance: About 0.1%. Stable isotope of barium.Barium-134
Natural abundance: About 2.4%. Stable isotope of barium.Barium-135
Natural abundance: About 6.6%. Stable isotope, NMR active.Barium-136
Natural abundance: About 7.9%. Stable isotope of barium.Barium-137
Natural abundance: About 11.2%. Stable isotope; barium-137m is produced from cesium-137 decay.Barium-138
Natural abundance: About 71.7%. Most abundant stable barium isotope.BaSO₄
Barium SulfateX-ray contrast agent, drilling mud, pigment and sulfate test precipitate.BaTiO₃
Barium TitanatePiezoelectric and dielectric ceramic for capacitors and transducers.Ba(NO₃)₂
Barium NitrateOxidizer and green-firework color source.BaCO₃
Barium CarbonateCeramics, glass and specialized chemical manufacturing.- Barium sulfate contrast suspensions for gastrointestinal X-ray imaging
- Barite, BaSO₄, as a high-density drilling mud additive in oil and gas wells
- Barium nitrate and barium chloride for green colors in fireworks
- Barium titanate piezoelectric and dielectric ceramics
- Barium sulfate as white pigment, filler and sulfate test precipitate
Barium has no essential biological role. Insoluble barium sulfate is safe enough for gastrointestinal X-ray contrast, but soluble barium salts are toxic because Ba²⁺ can disrupt potassium channels.
- Barium sulfate is useful medically precisely because it is extremely insoluble.
- Barium salts give a green flame, which makes barium important in fireworks.
- Barium titanate was one of the first major piezoelectric ceramics.
- The name barium refers to heavy minerals such as barite rather than unusually dense barium metal.
- Barium has atomic number 56 and belongs to group 2.
- Its electron configuration is [Xe] 6s².
- Barium commonly forms +2 compounds.
- BaSO₄ is insoluble and gives a white precipitate in sulfate tests.
What is the atomic number of barium?
The atomic number of barium is 56.
What is the electron configuration of barium?
Barium has the electron configuration [Xe] 6s².
What is barium used for?
Barium is used in X-ray contrast materials, drilling mud, green fireworks, barium titanate ceramics and pigments.
Why is barium sulfate used for X-rays?
Barium sulfate is dense and absorbs X-rays, but it is extremely insoluble, so it can pass through the digestive tract as a contrast agent.
What color is barium in a flame test?
Barium compounds produce a green flame.
Are barium compounds toxic?
Soluble barium compounds can be toxic, while insoluble barium sulfate is used safely under medical supervision as a contrast agent.