Some ions are sketched below. Rank them in increasing order of size of hydration enthalpy $H_{hyd}.$ That is$,$ select $1$ next to the ion with the smallest $H_{hyd}\text{'}$

select $2$ next to the ion with the next bigger $H_{hyd},$ and so on$.$

Note for advanced students: please compare the absolute magnitude of $H_{hyd}.$ For example, if $H_{hyd}=-1k\frac{J}{m}ol$ for the first ion and

$H_{hyd}=-2k\frac{J}{m}ol$ for the second ion, then the first ion has the smaller $H_{hyd}$ and the second ion has the bigger $H_{hyd}.$