|
As arsenic symbol, atomic number 33, atomic weight 74.93, the external electronic arrangement 4s24p3, covalent radius of 121 picometer , ionic radius As3-222 picometer, As +5 46 picometer, 859.7kJ/mol the first ionization energy, electricity negative 2.0. In the fourth cycle of group A � There are several major oxidation 3, +3 and +5. The common arsenic. With three allotropism : yellow-α, β - black and gray-γ. Room temperature is the most stable-γ, a marked nature of the metal, hard and brittle, 5.73g/cm3 density, the melting point of 817 ° C (2836.4kPa - -28 atmospheres), 613 ° C sublimation. Composition of gaseous molecules As4 (800 ° C). Free state arsenide sexual lively, in the air heated to 200 ° C with fluorescent, at 400 ° C showed a blue flame burning, and the formation of white smoke arsenic trioxide (As4O6), Yi with fluoride, nitrogen combination, in the heating and easy when most metals and non-metallic compound. Do not dissolve in water. Be Concentrated nitric acid or sulfuric acid oxidation arsenic, such as : HNO
3As +5 +2 +5 H2O = 3H3AsO4 NO
with molten sodium hydroxide produced by the reaction of sodium arsenite Na3AsO3 and release hydrogen. Soluble in aqua regia. Arsenic and its compounds are toxic. The arsenic is widely distributed in nature, mainly in the chemical form there, a small amount of free states. Li crustal abundances of 5.0 × 10 -4%, arsenopyrite important minerals are FeAsS, realgar AsS estrogen As2S3 yellow and white stone arsenic As2O3 so. The 1250 Rome Magnus with a total heat realgar found arsenic. The main purpose is to lead, copper, zinc alloy made, the system is also used medicines and insecticides and semiconductor materials such as gallium arsenide. Arsenic trioxide by reaction with carbon obtained.
Notice:Each item can have many explanations from different angels. If you want grasp the item comprehensively,please see below "more details data". |
Home Products Search Properties Search ä¸æ–‡ç‰ˆ