A student in CEM143 was doing a fractional distillation when she noticed that the temperature suddenly started to drop. What could have caused the decrease in the temperature

Explanation:

A process where two or more number of miscible liquids present in different fractions are separated by boiling at different temperatures is called fractional distillation.

The sudden decrease in temperature is because the compounds having lower boiling point have completed the distillation before vapor of the higher boiling point can actually fill the distillation head.

i'm assuming that it's c.) red bank..

a electronegativity decreases beacuse the size of nucleus is bigger.