Particle Physics
Test a particle collision against charge and momentum conservation.
Beams collide head-on. An electron and positron arrive with equal and opposite momentum, so the system starts with zero net charge and momentum.
A toy detector: an e⁺e⁻ collision starts with zero total charge and zero total momentum. Low energy scatters the pair, middle energy makes two back-to-back jets, and high energy makes a neutral pair that decays into ± tracks. “Fundamental” means no smaller constituents are known in the model, not that the object is a tiny classical ball.
Raise the beam energy and predict what the collision can make. The detector sees an event pattern; the conservation laws constrain its interpretation.
Make the idea yours.
Use the model, then answer without looking back. Each check isolates one decision a learner should be able to make after this lesson.