Cambridge Progression Test Stage 7 Science 2020 Paper 2

1. Biology: structure size hierarchy (organ system to cell), food web construction (Amazon species), decomposers and their role, penguin species classification using dichotomous key and height, life characteristics, decomposers′ feeding habits.
2. Chemistry: magnesium oxidation forming white powder (magnesium oxide), oxygen as diatomic molecule, particle diagrams of compounds, air composition pie chart (N₂, O₂, CO₂), acid-alkali reaction with pH change, conductor-insulator test using electrons.
3. Physics: energy transfer calculations (light to heat, sound to electrical), appliance energy diagrams, slinky sound wave model (compression, rarefaction), lunar eclipse Moon position identification, electric circuit symbol completion.
4. Earth science: Earth structure model (strengths and limitations), gas percentage change due to deforestation (CO₂ increase), water cycle stages (evaporation, condensation, precipitation), equipment to measure penguin height.
5. Scientific method: result reliability from pH experiment, comparison of pH probe vs indicator (precision), model improvement for Earth layers, drawing conclusions from pie charts, graph data interpretation.