In this Science Max Quiz, Phil explains how to differentiate chemical and physical changes. He mentions that chemical changes produce new molecules, while physical changes don't. He includes several examples of both physical and chemical changes.
Beakman explains how gas is explosive and causes the combustion engine in the car to work. He uses a model engine with a side view and demonstrates what is happening with the gasoline when it explodes to move the engine parts. Beakman shows how the engine allows the wheels to turn by relating it to riding a bike. Up and down motion of the pedals is converted to turning the wheels through the chain. Same in the car with the pistons turning gears and thus the wheels.
Josie acts like Madam Curie to explain how she discovered radiation and how it works. Beakman talks about how the fission of atoms produces heat, which makes radioactive materials glow. Beakman sets up a demonstration with mousetraps and ping pong balls (atoms) where he hits one and it causes a chain reaction of all of the mouse traps triggering.