Símbolo | Ar |
Número atómico | 18 |
Grupo | 18 (Gases nobles) |
Período | 3 |
Bloque | p |
Clasificación | Gases nobles |
Apariencia | Colorless gas exhibiting a lilac/violet glow when placed in a high voltage electric field |
Color | Incoloro |
Número de protones | 18 p+ |
Número de neutrones | 22 n0 |
Número de electrones | 18 e- |
Fase en STP | Gas |
Densidad | 1.784 g/cm3 |
Peso atómico | 39.792 u |
Punto de fusión | 83.81 K -189.34 °C -308.812 °F |
Punto de ebullición | 87.302 K -185.848 °C -302.5264 °F |
Entalpía de vaporización | 6.506 kJ/mol |
Electronegatividad (Escala de Pauling) | - |
Afinidad electrónica | -96 kJ/mol |
Estado de oxidación | 0 |
Energía de ionización |
|
Descubrimiento y primer aislamiento | Lord Rayleigh, William Ramsay (1894) |
Descubrimiento de argón Argon (Greek ἀργόν, neuter singular form of ἀργός meaning "lazy" or "inactive") is named in reference to its chemical inactivity. This chemical property of this first noble gas to be discovered impressed the namers. An unreactive gas was suspected to be a component of air by Henry Cavendish in 1785. Argon was first isolated from air in 1894 by Lord Rayleigh and Sir William Ramsay at University College London by removing oxygen, carbon dioxide, water, and nitrogen from a sample of clean air. They first accomplished this by replicating an experiment of Henry Cavendish's. |