Heavy metal 重金属

Looking from the density, the sky grey metal osmium is in the metal champion, the osmium density is 22.48 grams/cubic centimeters, quite Yu Qian 2 times, hard 3 times, lithium 42 times. 1 cubic meter osmium has 22.48 ton heavy. 　　The metal osmium is extremely crisp, places in the hard mortar to pound, very easily will turn the powder, the osmium powder assumes the blue black.　　The metal osmium is very stable in the air, the melting point is 2700 degrees Celsius, it does not dissolve in the ordinary acid, will not be corroded in the aqua regia. But, the powdery osmium, gradually will be oxidized under the normal temperature, and production perosmic anhydride. Perosmic anhydride when 48 degrees Celsius will melt, to 130 degrees Celsius when will seethe with excitement. The osmium vapor has the violent poisonousness, will stimulate the human eye intensely the mucous membrane, will be serious when will create loses one's sight. 　　The osmium may use in the industry to make the catalyst. When synthetic ammonia, if makes the catalyst with the osmium, may obtain the high conversion rate under not too high temperature. If mixes osmium in the platinum, may make is also hard the sharp scalpel.　　May make the iridium using the osmium identical quota's iridium. On the iridium-point pen pen tip that silver-white color's small dot, is the iridium. Iridium hard wear-resisting, the iraurita pen tip is more durable than the ordinary pen nib, key in this “small dot” on. May also make the clock and watch and the important instrument's bearing with the iridium, is very wear-resisting, can use many years, but will not damage.

从密度来看，蓝灰色的金属锇是金属中的冠军，锇的密度为 22.48 克/立方厘米，相当于铅的2倍，铁的3倍，锂的42倍。1立方米的锇就有22.48吨重。 　　金属锇极脆，放在铁臼里捣，就会很容易地变成粉末，锇粉呈蓝黑色。　　金属锇在空气中十分稳定，熔点是2700摄氏度，它不溶于普通的酸，甚至在王水里也不会被腐蚀。可是，粉末状的锇，在常温下就会逐渐被氧化，并且生成四氧化锇。四氧化锇在48摄氏度时会熔化，到 130摄氏度时就会沸腾。锇的蒸气有剧毒，会强烈地刺激人眼的粘膜，严重时会造成失明。 　　锇在工业中可以用做催化剂。合成氨时，如果用锇做催化剂，就可以在不太高的温度下获得较高的转化率。如果在铂里掺进一点锇，就可做成又硬又锋利的手术刀。　　利用锇同一定量的铱可制成锇铱合金。铱金笔笔尖上那颗银白色的小圆点，就是锇铱合金。锇铱合金坚硬耐磨，铱金笔尖比普通的钢笔尖耐用，关键就在这个“小圆点”上。用锇铱合金还可以做钟表和重要仪器的轴承，十分耐磨，能使用多年而不会损坏。