Physical and chemical properties of Gallium
Physical properties of Gallium:
Gallium is Light blue metal, which becomes a silvery white liquid at 29.76 °C. Liquid gallium is easily cooled and cooled to 0 ° C without curing. Slightly soluble in mercury to form gallium amalgam. Gallium can infiltrate glass, so it should not be stored in a glass container.
Gallium becomes liquid when heated to the melting point, and then cools to 0 ° C without curing. When the liquid is converted to a solid, its volume increases by about 3.2%. Hardness 1.5 to 2.5. Gallium is stable in dry air at room temperature.
Gallium is easy to hydrolyze, especially at physiological pH. Pure gallium is silver-white, can be infiltrated with glass, has a very high boiling point, and has a very low vapor pressure at about 1500 °C.
Melting point: 29.76 ° C
Boiling point: 2403 ° C
Density: 5.904 g / cm 3
Chemical properties of Gallium:
The peripheral electronic arrangement is 4s24p1, located in Group IIIA of the fourth cycle.
Oxidized in humid air, ignited when heated to 500 °C. It reacts slowly with water at room temperature, and reacts with boiling water to form gallium hydroxide to release hydrogen. Dissolved in mineral acid or caustic solution when heated.
Gallium is relatively stable in dry air and forms an oxide film that prevents further oxidation and tarnishes in humid air. It can be etched by cold concentrated hydrochloric acid, which is blunt to hot nitric acid. It can react with most non-metals at high temperature. In acid and alkali, gallium has +1, +2 and +3 valence in chemical reaction, of which +3 For its main valence.
Physiology of Gallium:
Gallium has not been found to function as a physiological trace element. Like aluminum, it is only slightly absorbed through the intestines.
Toxicological properties of Gallium:
The toxicity of gallium is related to the type of organism. In one study, mice had an LD50 greater than 220 mg/kg and dogs only 18 mg/kg. The death of the dog is due to the failure of kidney function.
Gallium and gallium compounds are weakly toxic, but there is no literature suggesting that gallium is reproductively toxic. In contrast, gallium nitrate can be used to treat certain diseases.
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