| General |
|---|
| Name | Argon | | Symbol | Ar | | Number | 18 | | Chemical series | Noble gases | | Group / Period | 18 / 3 | | Block | p-block | | CAS registry number | 7440–37–1 |
| Physical properties |
|---|
| State | gas | | Density | 1.784 g/L | | Melting point | 83.80 K (-189.35°C, -308.83°F) | | Boiling point | 87.30 K (-185.85°C, -302.53°F) | | Critical point | 150.87 K, 4.898 MPa |
| Atomic properties |
|---|
| Atomic Weight | 39.948 g/mol | | Crystal structure | cubic face centered | | Electronegativity | | | Atomic radius | 71 pm | | Atomic radius (calculated) | 71 pm | | Electron configuration | [Ne] 3s2 3p6 | | Electrons per shell | 2, 8, 8 | | Number of protons | 18 | | Number of neutrons | 22 |
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Potassium