Quick answerBarium (Ba) is an alkaline earth metal with atomic number 56 and an atomic mass of 137.33 (2023), in group 2, period 6. It was discovered by Humphry Davy in 1808. It is used for X-ray contrast meals and fireworks. Its electron configuration is [Xe] 6s2.
Barium is the heavy metal patients swallow as a chalky meal so doctors can X-ray their stomachs and intestines.
Key facts
| Symbol | Ba |
|---|---|
| Atomic number | 56 |
| Atomic mass | 137.33 (IUPAC standard atomic weight, 2023) |
| Category | alkaline earth metal |
| Group | 2 |
| Period | 6 |
| Block | s-block |
| Electron configuration | [Xe] 6s2 |
| Discovered | Humphry Davy, 1808 |
| Uses | X-ray contrast meals, fireworks, glass production, oil drilling fluids, pigments |
Quick quiz
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Keep exploring
- Periodic table — all 118 elements
- Beryllium (Be) — another alkaline earth metal, atomic number 4
- Magnesium (Mg) — another alkaline earth metal, atomic number 12
- Calcium (Ca) — another alkaline earth metal, atomic number 20
- Strontium (Sr) — another alkaline earth metal, atomic number 38
- Radium (Ra) — another alkaline earth metal, atomic number 88
Sources & last updated
- CIAAW — Standard Atomic Weights
- PubChem Periodic Table
- Wikipedia — Timeline of chemical element discoveries
Last updated: . Figures are shown with their year; where sources disagree, the value is left out rather than estimated.