为什么科学家关心它
Periodic trends is part of the shared Mendeleev scientific core. This page is intentionally conservative until more native-language terminology is verified.
一个具体例子
Across period 3, atomic size generally falls while first ionization energy generally rises, with instructive exceptions.
值得注意
当一个定义与可测量或可观察的现象连接起来时，科学才真正容易记住。