These are finite task opportunities, not proof of mastery. Record what was attempted and what support was used.

• Supplied joules are illustrative, not observed measurements.

• Canonical closed-system statement retained in provenance but qualified in teaching.

• These bounded source-based examples and task opportunities do not establish learner mastery or general scientific performance.

Use the supplied paper cases only unless the optional paper prototype test is explicitly chosen. Do not handle electrical chargers, heat materials, mix chemicals, approach floodwater or volcanoes, or disturb animals. For the optional prototype, an adult checks a clear tabletop; use only paper and a blunt pencil, keep paper away from faces, and stop if the setup feels unsafe. Missing equipment, discomfort or no test means not performed: leave observations blank. No personal health, disaster or family experience is required.

Retain your actual plan and observations on paper between steps. If not performed, leave results blank. Record response mode and assistance; do not infer mastery.