Chemical Concept(s) Demonstrated: Boyle's Law and the concepts of force and pressure
The syringe's volume decreases as more books are placed on its plunger.
The textbooks create a force that presses down on the plunger of the syringe. The gas inside of the syringe is now compressed into a smaller space, and the intermolecular collisions become more and more frequent. This frequency results in an increase of pressure inside of the syringe, which pushes back against the books. The pressure increase is related to the volume decrease of the gas in the syringe. A plot of 1/V versus the number of books should be linear.