Jayden was given a marshmallow and a syringe in class to experiment with. she placed the marshmallow in the syringe and sealed the end. when she depressed the plunger of the syringe what happened to the marshmallow and why?

The increased pressure, pushed the molecules closer together, and caused the marshmallow to shrink.

Explanation:

This follows Boyle’s law which states that pressure is inversely proportional to volume given that temperature is unchanged, (remains constant).

When Jayden presses the plunger, with a sealed end in order to stop the marshmallow from falling out, there is increased air pressure in the syringe, this increased pressure will push against the marshmallow causing it to shrink (reduce in volume). This justifies Boyle’s law, the syringe pressure is increased and consequently, the  marshmallow volume is decreased.