水合离子半径怎么比较？为什么Li+>Na+>K+>Rb+>Cs+？难道离子半径大的水合离...

离子半径的顺序就是水合离子半径顺序。
“Li+>Na+>K+>Rb+>Cs+ ”的半径顺序是不可能的，应该是正好相反：
Li(+) < Na(+) < K(+) < Rb(+) < Cs(+)
如果是水合热，则是Li(+)的放热最多，Cs(+)的放热最少；半径越小，离子的水合热最大。所以是不是弄错概念了。

你说的是对的，离子半径大的水合离子半径小。
For ions with the same charge, such as Li+ and K+, small ion has larger size of hydrated ion. This is due to the its larger charge density, and hence, larger coulombic force with water molecules.

For ions with different charges, such as Mg2+, and Li+, larger of the charge, smaller size of the hydrated ion.

金属活动性决定，金属活动顺序在前的半径小