银器对光不敏感,也不怕冷,但在大气中,它易受有害物质侵蚀,而使颜色变得晦暗、发黑,这不仅影响美观,而且在腐蚀严重时,银器的金属本体已不存在,此时器物变得又黑又脆,整件就可能被腐蚀而毁坏。由于常用的燃料(煤和石油)中含有硫,所以大气中总会存在少量H_2S。在一定湿度下,它们和空气中的氧,发生如下反应,使银变色: 4Ag+2H_2S+O_2=2Ag_2S+2H_2O Silverware is not sensitive to light nor cold, but in the atmosphere, it is susceptible to the attack of harmful substances, leaving the color dull and dark, which not only affects the appearance, but also in the case of serious corrosion, the metallic body of silverware Does not exist, then the utensils become dark and brittle, the whole piece may be corroded and destroyed. Since sulfur is commonly used in fuels (coal and oil), there is always a small amount of H2S in the atmosphere. Under certain humidity, they react with the oxygen in the air in the following reaction to discolor the silver: 4Ag + 2H_2S + O_2 = 2Ag_2S + 2H_2O