Which physical property is lower for alkaline earth metals as compared to alkali metals of the same period ?

Ionisation Potential : IA < IIA→ Alkaline earth metals are harder when compared to alkali metalsReason :1 Due to their small2 Due to involvement of two valency electrons in metallic bond formation the inter atomic attraction strong. Therefore in order to break up those attraction force high amount of heat [Energy] required i.e., they possess high melting points→ As size decreases, their valency electrons are strongly held by the nucleus inorder to remove those electrons high energy is required, i.e., high I.E is required As size decreases I.E decreasesTherefore electron loosing tendency decreases  Electro positivity  decreases