Gretchen explains the rules of the lunch table to Cady. The rules cover how each member of The Plastics should behave and dress on different days of the week. If an individual doesn't follow the rules, then that person will not be able to sit with The Plastics at lunch that day.
Beakman explains who made the toilet and then shows a cross-section of a toilet to show the inside. Then he uses colored water to show how gravity pushes the waste out of the toilet into the drain. He then shows how the back tank of the toilet works with valves and gravity to push the water in the toilet bowl down into the drain.
Beakman demonstrates force and pressure with a balloon sitting on one nail with a brick on it (it pops) and then how it doesn't pop if you have more nails to distribute the pressure of the force. He shows how this also applies to cutting a tomato. Then Beakman lays on a bed of nails to prove it.
Phil conducts an experiment involving hot water, a flask, and an egg. He fills the flask with hot water, dumps out the water, then plugs the flask with the egg. Phil explains that the egg gets pulled into the flask by the difference in pressure outside and inside the flask. Phil then explains how to get the egg out of the flask: by increasing the pressure inside the flask using his breath.