第84号元素钋(Polonium,po.)是居礼夫人于1898年发现的,因为这元素所可获得的量太少了,所以关于它的物理性质等,居礼夫人亦没有法子测定。直到最近由于原子能研究发展的结果,才获得了这种金属的单体,其外形和物理性都和铅相像,但加热时,体积收缩,这和他种金属加热时体积膨胀的性质正相反。还有,纯粹的钋内具有立方形的晶体结构,这在其他元素中也从未见过,故尚未有确切的理论可以解释。 Polonium (po.) Was discovered by Mrs. Gurury in 1898 because too little was available for the element, so Mrs. Julie did not measure her physical properties. Until recently, as a result of the development of atomic energy, the monomer of this metal was obtained. Its shape and physical properties were similar to that of lead, but when it was heated, it contracted in volume, which was the opposite of the volume expansion when heated with other metals. In addition, there is a cubic crystal structure within the pure 钋, which has never been seen in other elements, so there is no exact theory to explain.