Ba
Barium compounds are used in medical imaging and produce green fireworks.
Physical Properties
| Atomic Mass | 137.33 u |
| Density | 3.594 g/cm³ |
| Melting Point | 1000.0 K |
| Boiling Point | 2170.0 K |
| Appearance | Silvery gray metallic |
| State at Room Temp | Solid |
Chemical Properties
| Electronegativity | 0.89 (Pauling) |
| 1st Ionization Energy | 502.9 kJ/mol |
| Electron Affinity | 13.95 kJ/mol |
| Oxidation States | +2 |
Atomic Properties
| Electron Configuration | [Xe] 6s2 |
| Atomic Radius | 222.0 pm |
| Covalent Radius | 215.0 pm |
| Van der Waals Radius | 268.0 pm |
Discovery
| Discovered By | Carl Wilhelm Scheele |
| Discovery Year | 1772 |
| Location | Uppsala, Sweden |
| Named After | Greek 'barys' meaning heavy |
About Barium
Barium is a soft, silvery alkaline earth metal never found pure in nature. Barium sulfate is used as a radiocontrast agent for digestive X-rays. Barium compounds produce green colors in fireworks.
Uses & Applications
Medical X-ray imaging, oil drilling fluids, fireworks (green color), glass, and rat poison.
Fun Fact
Patients drink barium sulfate before X-rays -- barium is toxic, but the sulfate form is so insoluble it passes through safely.
Isotopes
| Mass Number | Abundance | Half-Life | Stable |
| 134 | 0.02417% | - | Yes |
| 136 | 0.07854% | - | Yes |
| 137 | 0.11232% | - | Yes |
| 138 | 0.71698% | - | Yes |
Electron Configuration
[Xe] 6s2