Answer: It decreases because nonvolatile aluminum and chloride ions now occupy some of the volume of the system.
Explanation:
Vapor pressure of a liquid is defined as the pressure exerted by the vapors in equilibrium with the liquid/solution at a particular temperature.
So, when a non-volatile solute is added to a solvent then its molecules align at the surface of liquid. As a result, less number of solvent molecules will escape from the solution. Thus, there will be decrease in vapors and thus the vapor pressure decrease.
The relative lowering of vapor pressure is directly proportional to the amount of dissolved solute.
Energy of the reactants would be correct
The principal thing that one can read from a periodic table is the atomic number which is the number in the box that the element symbol appears and it means the number of protons in the nucleus of its atom and this number determines its chemical properties and is unique for each chemical element. The table is color coded to show the different types of elements ie "transition metals, alkali metals, noble gases" etc. and these different types are grouped together.
