I believe it would be milk souring.
The answer would be the third option. (the angle at which the light hits the surface.)<span>
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You can differentiate between ionic, covalent and molecular compounds by the fact that ionic compounds contain elements that include both a metal and a nonmetal. Molecular compounds contain both non metals covalently bonded to each other. While acids most often on their chemical formula start with the element of Hydrogen - H.
For Eg - sulphuric acid
H2SO4
hydrochloric acid - HCl.
Because the intention is to boil the solution, the purpose of the solvent is to dissolve so it has a higher boiling point so ensure it stays in liquid form and doesn't evaporate into a gas
also, a pure solvent is made of 1 substance so it has 1 boiling point and the solution must evaporate/boil first
12% NaCl is the answer I came to... Have a GREAT day!!! :)