56Ba137.33
Barium
Alkaline Earth Metal
Solid at STP
Period 6Group 2Block SDiscovered 1808
[Xe]6s2
Barium is a chemical element with symbol Ba and atomic number 56. It is the fifth element in Group 2, a soft silvery metallic alkaline earth metal. Because of its high chemical reactivity barium is never found in nature as a free element.
📖 Read more on Wikipedia →Atomic Properties
| Atomic Number | 56 |
| Atomic Mass | 137.33 u |
| Electron Configuration | [Xe]6s2 |
| Oxidation States | +2 |
| Electronegativity | 0.89 (Pauling) |
| Atomic Radius | 268 pm |
| Ionization Energy | 5.212 eV |
| Block | S |
Physical Properties
| Standard State | Solid |
| Melting Point | 1000 K (726.9 °C) |
| Boiling Point | 2170 K (1896.8 °C) |
| Density | 3.62 g/cm³ |
| Molar Heat | 28.07 J/(mol·K) |
| CPK Color | #00C900 |
Classification
| Category | Alkaline Earth Metal |
| Group Block | Alkaline earth metal |
| Period | 6 |
| Group | 2 |
| Block | S |
Discovery
| Year Discovered | 1808 |
| Discovered By | Carl Wilhelm Scheele |
| Electron Shells | 2, 8, 18, 18, 8, 2 |