How many of the following oxides are amphoteric?
$BeO, ZnO, Sb_2O_3, CO, CaO, SO_2, SO_3$

The thermal stability of alkaline earth metal carbonates $MgCO_3$,$CaCO_3$,$BaCO_3$,and $SrCO_3$ decreases as:

Choose the correct statements from the following:
$(I)$ In vapour phase $BeCl_2$ exists as a chlorobridged dimer.
$(II)$ $BeSO_4$ is readily soluble in water.
$(III)$ $BeO$ is completely basic in nature.
$(IV)$ $BeCO_3$ being unstable, is kept in an atmosphere of $CO_2$.
$(V)$ $BeCO_3$ is the least soluble among all the carbonates of group $2$ elements.

The compounds of alkaline earth metals have the following magnetic nature:

Which of the following is true for magnesium?

Which of the following ions has a higher hydration enthalpy than the $Mg^{2+}$ ion?