1. Human biology and gas exchange: alveoli structure and adaptation (diffusion surface), oxygen-rich blood region, iron for red blood cells 2. Chemical reactions: magnesium with oxygen and hydrochloric acid, product identification, Bunsen burner safety, control of risks 3. Electromagnetism: variable current effect on pin attraction, anomaly recognition, alternative strength factors 4. Space science: solar system, galaxy, stellar dust, satellites, part-description matching 5. Ecology and bioaccumulation: food chain concentration increase (e.g. otters), habitat identification, toxic buildup explanation, ecological impact 6. Dissolving and concentration: particle model diagrams, solute vs solvent identification, solution darkness related to concentration