Safety and evidence boundary
Use supplied data, paper or digital models, and approved simulations unless a separately supervised laboratory protocol is provided.
Explicit science instruction
A scattering experiment produces a distribution, not one dramatic event. Both common and rare outcomes matter when models make different predictions.
In a nuclear model, most projectiles pass far from the compact positive region and deflect little; close approaches can produce much larger deflections.
A useful model must explain the full pattern, including the rare tail.
Vocabulary: deflection angle; frequency distribution; electrostatic repulsion; rare event; evidence constraint.
Worked example with reasoning
Synthetic data: 9,900 particles deflect under 5°, 92 deflect 5–30°, 7 deflect 30–90°, and 1 exceeds 90°. The rare high-angle group is small but highly informative.
Guided question
Calculate the percent of particles in each category and identify which group most strongly challenges a diffuse-positive model.
Independent work
- Graph the four deflection categories.
- Write a bounded claim about nucleus concentration.
- Name one measurement limitation that affects exact percentages without erasing the overall pattern.
Misconception check
Rare observations are not automatically errors; repeatable rare events can be decisive evidence.
Formative understanding check
If 99% of particles travel almost straight, should the remaining 1% be ignored?
Reveal worked response
No. The minority pattern may contain the evidence that distinguishes competing models.
Public self-check only.
Mentor evidence conference
Ask Archaemenes to test whether your interpretation uses the full distribution.
Archaemenes may challenge reasoning and help plan corrections, but does not grant official mastery.
Teacher guidance
Foundation: Compute one percentage and identify the high-deflection tail.
Core: Graph all categories and connect the distribution to a nuclear model.
Extended: Discuss how measurement resolution could influence the observed distribution.