The complex formation tendency of alkaline earth metals decreases down the group because

Which one of the following statements is $NOT$ correct about the compounds of alkaline earth metals?

The number of electrons and protons in the third alkaline earth metal ion $(Ca^{2+})$ will be:

$A$ metal $M$ readily gives $MSO_4$,which is soluble in water. It forms its oxide $MO$ which is amphoteric. It forms an insoluble hydroxide $M(OH)_2$,which is soluble in $NaOH$ solution. The $M$ is

Which of the following elements is chemically most reactive?

Identify correct statements from the following:
$i$. Beryllium oxide is an amphoteric oxide.
$ii$. Group $II$ elements dissolve in liquid ammonia to form deep blue-black solutions.
$iii$. The hydration enthalpy of group $II$ ions decreases from $Be^{2+}$ to $Ba^{2+}$.