if you add sugar to water and the sugar no longer dissolves and it settles at the bottom the solution has become

It forms a solution.

Explanation:

A pure substance is when only one type of atom or molecule is present. In this case the substance contains two different molecules; sugar and water, assuming sugar is all one type (e.g. glucose) and there are no contaminants in the water or sugar before combining the two.

Dissolving the sugar in the water makes a homogeneous mixture and once dissolved a solution is made by the combination of a solute (sugar) and solvent (water).

Hope this helps

i just calculated it all out, and not including weekends, and all the different days off. as of this school year (2018-2019) students are spending 2198 hours in school this year

"record the time to complete a chemical reaction" would most likely be part of a lab procedure.