How does the composition of the liquid at the top of the fractional distillation column compare with the composition of the liquid at the bottom of the column?

The top of the fractional distillation column will have a more volatile liquid as compared to the liquid at the bottom.

Explanation:

Fractional distillation is the method of separating liquids with different boiling points.For example,ethanol can be separated from water from a ethanol-water mixture.The component with a lower boiling point will pass in the column and collected first followed by higher boiling point component.Repeated vaporization and condensation results in the separation of the components in the mixture.

c- cold periods in earth's history during which glaciers covered much of the surface.

explanation: