Answer:

Raoult's law states that the vapor pressure of a solvent above a solution is equal to the vapor pressure of the pure solvent at the same temperature scaled by the mole fraction of the solvent present: Psolution=χsolventPosolvent.
Answer:
to have a "full" last orbital shell
Explanation:
They can not live withought ther outer most shell
(2) Mg, Ca, and Ba have the most similar chemical properties, and we know this because of their coexistence in the group alkali earth metals (group 2) on the periodic table.