Question

An example of a physical property of an element is the element’s ability to(1) react with an acid(2) react with oxygen(3) form a compound with chlorine(4) form an aqueous solution

Answer 1

4: Form An Aqueous Solution 

This is the only answer that can be observed without testing gear and with the naked eye.... Hope I helped ^-^

Answer 2

Answer is: 4) form an aqueous solution.

Physical property can be observed and measured without any changes in molecular composition. The same substance is present before and after the change.  Making aqueous solution is physical change (solvatation).

Element reactions with acids, oxygen and chlorine are chemical change (chemical reaction combustion), because new substances are formed, the atoms are rearranged and the reaction is followed by an energy change (exothermic reaction because energy is released).