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Goal: Predict likely ion charges for selected main-group atoms and justify a comparison using the supplied model.

Before this: Know proton, electron and net electric charge.

Try together: Together use the given pattern to explain why Na+ and Cl− have opposite charges despite both being described as reaching a filled outer shell in the simplified model.

Goal: Use two supplied properties to compare possible interaction models and identify a needed measurement.

Before this: Distinguish melting from dissolving.

Try together: Together mark which statements in the report are observations and which are inferences. Ask whether the same-pressure condition matters.

Goal: Calculate a product amount from a limiting supplied reactant and explain the conserved atom counts.

Before this: Read formulas and multiply ratios.

Try together: Together find the product when 3 mol H2 and 3 mol O2 are supplied. Identify the limiting reactant before subtracting leftovers.

Goal: Use supplied bond-energy values to calculate net change and distinguish bond breaking from bond formation.

Before this: Use signed numbers and recognize molecular bonds.

Try together: Together calculate a second model requiring 700 kJ to break bonds and releasing 550 kJ on formation; describe the sign in words.

Goal: Calculate two average rates and explain a collision-model hypothesis with a limitation.

Before this: Read concentration and elapsed-time data.

Try together: Together explain why “B ends with 1.75 times as much product” is not established by these first-20-second observations.

Goal: Recommend and justify one system change that increases product while explaining dynamic equilibrium.

Before this: Read a reversible equation and distinguish rate from amount.

Try together: Together critique “Equilibrium requires one-third each A, B and C.” Use the distinction between equal rates and equal quantities.