晴雨花很奇妙:晴天,它是蓝色的;即将下雨的阴天,它变成紫色;下雨天,它呈现出鲜艳的玫瑰色。晴雨花当然不是真正的花,而是人工做成的假花。人们把滤纸浸泡在一种特殊的溶液里,晾干后把滤纸剪成花瓣,拼贴起来就做成可以预知晴雨的花来了。这种奇特的溶液便是金属钴的盐类(二氯化钴)溶液。钴是瑞典化学家布朗特(Brandt.G.1694—1768)于1735年从辉钴矿(CoAsS)中还原而发现的。人类使用钴是从制造有色玻璃开始的。古希腊人、罗马人、埃及人都 Sunny rain flowers are wonderful: sunny, it is blue; the upcoming cloudy, it becomes purple; rainy day, it presents a bright rose. Of course, rain flowers are not real flowers, but artificial artificial flowers. People soak the filter paper in a special solution, dry the filter paper into petals, collage it up to be able to predict the flowering of the rain. This peculiar solution is a solution of metallic cobalt salts (cobalt dichloride). Cobalt was discovered by Swedish chemist Brown (Brandt. G. 1694-1768) in 1735 from cobalt-cobalt (CoAsS). Human use of cobalt begins with the manufacture of colored glass. Ancient Greeks, Romans, Egyptians all