元素周期系的“时空限制”

本文从“时”“空”两个方面讨论了元素周期系的界限。铀后元素是不稳定的,随着原子序数的增加,半衰期迅速变短,作为不稳定核的存在受到可测时间的限制,可测时间的理论极限应是强相互作用时间10~(-23)秒。铀后元素最长寿同位素的半衰期τ(年)与原子序数Z有近似线性关系lgτ=-1.173Z+116.7,由此得出不稳定核存在的时间限制是Z=125;空间限制是Z=131～153。“时”“空”限制基本相一致,使得有理由认为周期系的极限界限在第八周期。

THE TIME-SPACE RESTRICTION OF THE PERIODIC SYSTEM

The boundary limit of the periodic system is discussed from both time and space respect in this paper- Transuranic element is unstable.The half-lifes of the elements become rapidly shorter to follow the increase in atomic number.The existence of the unstable nucleus is restriced by the possible measured time.The theoretical limit of the possible measured time is the strong interaction time 10~(-2 3) second.The halflifes τ(year)of the longest life isotopes of transuranic elements vary with atomic number Z according to the following approximate linear relation lgτ =-1.173Z-116.7.Hence the boundary limit of unstable nucleus in time-restriction,Z=125,is abtained.That in space-restriction is Z=131-153.The boundary limit in time-restriction is agreement with that in space-restriction in principle.It is reasonble that the final limit of the periodic system is with in 8th period.