Chemical Reactions and Equations — Evidence, Balancing and Patterns
3 lessons · 24 original choice questions · 12 controlled visual states
- Read evidence and chemical equations
- Balance by conserving atom counts
- Recognise combination and decomposition
GRADE 10 · SCIENCE · CHAPTER 1
Chemical Reactions and Equations
Six lessons across two linked companions, using atom models and supplied observations.
Selected theory outcomes and paper reasoning are available. Full textbook exercise solutions, supervised laboratory performance and independent teacher review remain pending.
Chemical Reactions and Equations — Exchange, Energy and Redox
3 lessons · 24 original choice questions · 12 controlled visual states
- Explain displacement and precipitation
- Reason about energy transfer
- Connect oxidation, reduction and everyday effects
Evidence for each outcome
Read evidence and chemical equations
Separate an observation from a conclusion, then identify reactants, products and physical states.
Paper task: make two columns headed Observation and Inference. Sort “temperature rose by 5 °C” and “energy was released” into them, then state what extra information would strengthen the inference. Do not mix household chemicals.
Open the guided lesson sequenceBalance by conserving atom counts
Balance a supplied equation with the smallest whole-number coefficients and verify every element.
Use labelled paper counters for atoms. Rearrange the same counters from one side to the other; record the count of each element before and after. The paper model does not demonstrate real reaction conditions or rate.
Open the guided lesson sequenceRecognise combination and decomposition
Classify reaction patterns by the number of different reactant and product substances.
On paper, sort supplied equation cards by pattern. Add a separate “energy evidence not supplied” column so classification does not become a guess about temperature.
Open the guided lesson sequenceExplain displacement and precipitation
Use a supplied reactivity order and recognise an insoluble product in a double-displacement reaction.
Make paper cards labelled Ca²⁺, CO₃²⁻, Na⁺ and Cl⁻. Pair Ca²⁺ with CO₃²⁻ in a “solid” box and leave two Na⁺ and two Cl⁻ in a “solution” box. Check both atom counts and charge balance. Do not handle laboratory reagents.
Open the guided lesson sequenceReason about energy transfer
Distinguish exothermic from endothermic change and judge temperature evidence with stated conditions.
On paper, draw the system boundary and an energy arrow for each supplied data card. Add one possible interfering factor, such as an external heater or heat exchange with room air. This is data interpretation, not a chemical experiment.
Open the guided lesson sequenceConnect oxidation, reduction and everyday effects
Track oxygen transfer and explain how exposure affects corrosion and rancidity.
Given a teacher’s photo or written record of a painted iron item with rust at a scratch, explain the exposed-surface mechanism. For food, compare only supplied packaging/storage data; never taste unknown or spoiled samples.
Open the guided lesson sequence