Interactive Chemistry Lesson Ideas with Simulations

These interactive chemistry lesson ideas give you ten activities that run on free simulations, from building an atom to measuring the voltage of a galvanic cell. Chemistry is hard to teach because the action happens at a scale nobody can see. A simulation puts the particles on screen next to the measurements, so students can link "the solution turned darker" to "the equilibrium shifted toward NO₂". It also lets them run experiments you would never allow on a school bench, such as electrolysis of molten salt. Each idea below lists the grade level, a driving question, what students do and the result they should get, with numbers checked against the simulation. Students open everything on Simulic from a link or QR code, with no account.

This guide goes deeper than the chemistry example in how to use interactive simulations in the classroom and uses different simulations.

Atoms and bonding

1. What changes when you add one particle to an atom?

Grades 6–9 · Build an atom

Driving question: Which particle decides what element you have?

1. Start from the default: 6 protons, 6 neutrons, 6 electrons. Students name it and give the mass number.
2. Add two neutrons. Then, separately, add one proton instead. Compare the cards.
3. Build sodium (11 p, 12 n, 11 e) and remove one electron.
4. Switch Mode to Challenge and complete five tasks.

Expected result: the default is carbon-12. Two extra neutrons give carbon-14, still carbon but radioactive, with a half-life of 5,730 years. One extra proton turns it into nitrogen. Sodium minus one electron is Na⁺ with shells 2, 8, the same arrangement as neon.

2. Why is CO₂ nonpolar when its bonds are polar?

Grades 9–11 · Molecule polarity

Driving question: Can a molecule made of polar bonds be nonpolar overall?

1. On the Two Atoms screen, the defaults give χ = 2.0 and 3.0. Read Δχ and the bond type. Raise atom B to 3.8.
2. On the Three Atoms screen (A = 3.0, B = 2.2, C = 3.0 at 120°), drag the angle to 180° and watch the molecular dipole.
3. On Real Molecules, compare CO₂ with H₂O, then BF₃ with NH₃.

Expected result: Δχ = 1.0 is polar covalent; at 3.8, Δχ = 1.8 crosses the 1.7 line into ionic. At 120° the bond dipoles add to a net dipole, while at 180° they cancel. CO₂ and BF₃ are symmetric and nonpolar; bent H₂O and pyramidal NH₃ are polar. Pair this with molecule shapes (VSEPR) for the 3D angles.

States of matter and gases

3. Why does water boil so much higher than neon?

Grades 6–10 · States of matter – solids, liquids, gases

Driving question: What is different about the particles in a solid, a liquid and a gas, and why do substances melt and boil at different temperatures?

1. On the States screen, heat solid argon slowly. Students describe the motion at each stage in one sentence.
2. Cool it back down and watch it re-form.
3. Open the Interaction potential screen and compare the well depths of neon, argon, oxygen and water.

Expected result: particles vibrate in place in the solid, slide past each other in the liquid and fly freely in the gas. Water's well is about 34 meV deep, against 3.1 meV for neon, more than ten times deeper. Stronger attraction means more energy is needed to pull particles apart, so the boiling point is higher.

4. Why must gas temperatures be in kelvin?

Grades 10–12 · Ideal gas – pV = nRT

Driving question: If you double the temperature of a gas in a sealed container, does the pressure double?

1. Read the default state: 1 mol, 300 K, 20 L.
2. Choose the isochoric p–T graph. Set T to 600 K and read the pressure.
3. Ask: "27 °C to 54 °C is also doubling. Will the pressure double?" Convert to kelvin and test.
4. Switch to the isothermal graph and halve the volume.

Expected result: the default pressure is about 124.7 kPa (1.23 atm). At 600 K it doubles to about 249 kPa. Going from 27 °C to 54 °C is only 300 K to 327 K, a 9% rise. Halving the volume to 10 L also doubles the pressure.

Solutions, acids and bases

5. Same moles, same volume: same concentration?

Grades 8–10 · Molarity

Driving question: If you dissolve 0.5 mol of a solid in 0.5 L of water, is the concentration always 1 mol/L?

1. Start with the defaults: 0.5 mol of copper(II) sulfate in 0.5 L. Read the concentration and the mass dissolved.
2. Halve the volume, then double it. Students predict the color each time.
3. Switch the solute to potassium permanganate with the same amounts.

Expected result: copper sulfate gives 1.00 mol/L, with 79.8 g dissolved. Concentration doubles when the volume halves. Potassium permanganate saturates at 0.40 mol/L, so 0.3 mol stays as crystals on the bottom. Solubility limits the concentration, and the formula C = n/V only applies to what dissolves. For absorbance and color, extend with Beer's law.

6. Does adding water make an acid less acidic?

Grades 6–9, extension for 11–12 · pH scale

Driving question: What happens to the pH of coffee if you add water? If you pour half of it away?

1. In the Macro screen, measure coffee with the probe (pH 5.0).
2. Hold "add water" for a few seconds and read the pH. Then hold "drain".
3. In the Micro screen, compare the H₃O⁺ and OH⁻ bars on the log scale for battery acid, water and drain cleaner.

Expected result: adding water moves the pH toward 7. Draining changes the volume but not the pH, because concentration doesn't depend on how much you have. At pH 5, [H₃O⁺] = 10⁻⁵ mol/L, a hundred times more than in neutral water. For grades 11–12, open strong vs weak acids: at 0.1 M, HCl has pH 1.00 and ethanoic acid about 2.88, roughly 76 times less H⁺, yet both give the same 60 mL of hydrogen with magnesium in the end.

Reaction rates and equilibrium

7. Does powder make more gas, or just make it faster?

Grades 9–11 · Measuring gas volume over time

Driving question: Calcium carbonate reacts with acid. Does crushing it change the final amount of CO₂ or only the speed?

1. Run the defaults: 0.4 g CaCO₃ lumps, 1.0 M HCl, 25 °C. Note the final volume and the half-time in the table.
2. Press New run, switch to powder and run again.
3. New run with lumps at 35 °C.
4. Drag the t₁ and t₂ markers to find the average rate over the first 30 s of each run.

Expected result: every run ends at about 99 mL of CO₂, because the 4 mmol of CaCO₃ is the limiting reactant. Powder gives a much steeper start. A 10 °C rise doubles the rate, so the half-time halves. Run it before a real gas-syringe practical, so students know what shape of curve to expect and which factor to change.

8. Which way does the equilibrium shift?

Grades 11–12 · Chemical equilibrium – N₂O₄ ⇌ 2NO₂

Driving question: The forward reaction is endothermic. What happens to the color when you heat the flask, and when you squeeze it?

1. Let the defaults settle (25 °C, 2 L, 0.1 mol N₂O₄). Read K and the degree of dissociation.
2. Raise the temperature to 50 °C.
3. Reset, then reduce the flask volume to 1 L and watch the color in the first seconds and after it settles.
4. Press Add NO₂ and ask for a prediction before the graph levels out.

Expected result: at 25 °C, K ≈ 0.006 and about 16% of the N₂O₄ is dissociated. At 50 °C, K rises to about 0.018 and dissociation to 26%: darker brown. Compression darkens the gas at once, then it fades a little as dissociation drops to about 12%. The new color is still darker than before, because [NO₂] ends at 0.023 M instead of 0.016 M. Le Chatelier "opposes" a change; it doesn't undo it.

Stoichiometry and electrochemistry

9. Which reactant runs out first?

Grades 8–10 · Balancing chemical equations and Reactants, products and leftovers

Driving question: You have 4 molecules of H₂ and 3 of O₂. How much water can you make, and what is left?

1. Balance the three Intro reactions in the balancing simulation, then play Game level 1.
2. In the leftovers simulation, start on the Sandwiches screen, then open Molecules → Make water with 4 H₂ and 3 O₂.
3. Students predict the products and leftovers, then check against the atom count table.

Expected result: 2H₂ + O₂ → 2H₂O. Four H₂ make 4 H₂O and use only 2 O₂, so 1 O₂ is left. H₂ is the limiting reactant even though there are "more" molecules of it. Methane combustion balances as CH₄ + 2O₂ → CO₂ + 2H₂O.

10. Which metal pair makes the best battery?

Grades 11–12 · Galvanic cells and electrolysis

Driving question: Can you predict the voltmeter reading before you build the cell?

1. In galvanic cell mode, students use the E° values to predict the cell potential for Zn–Cu, then check.
2. Go through the other pairs and rank them.
3. Switch to electrolysis of CuSO₄ with inert electrodes at 2 A. Read the copper mass after 10 simulated minutes, then repeat at 4 A.

Expected result: Zn–Cu reads 1.10 V. Mg–Cu gives the largest, about 2.70 V, and Cu–Ag the smallest, 0.46 V. Zinc dissolves and copper deposits. Electrolysis at 2 A for 10 minutes deposits about 0.40 g of copper; 4 A doubles it. NaCl solution gives hydrogen at the cathode, not sodium. Only molten NaCl produces the metal.

Which idea fits which lesson?

Idea	Best moment	Question to attach
1. Build an atom	First lesson on atomic structure	Short text: what makes carbon-14 carbon?
3. States of matter	Opening the particle model	Prediction: what happens to the particles when a solid melts?
4. Ideal gas	After introducing pV = nRT	Number: pressure at 600 K (249 kPa ± 2)
5. Molarity	Before a practical on making solutions	Number: concentration of 0.5 mol in 0.25 L (2.0 mol/L ± 0.05)
7. Gas volume	Before or instead of a rates practical	Multiple choice: lumps vs powder, final volume
8. Equilibrium	Introducing Le Chatelier's principle	Prediction: color after heating
10. Electrochemistry	Revising electrode potentials	Number: Zn–Cu cell potential (1.10 V ± 0.02)

How to run these in class

Chemistry ideas work best when students commit to a particle-level explanation before they look. Three ways to set that up:

• Projector first, devices second. Run ideas 3 and 8 on the projector in present mode (add ?present=1 to the link), collect predictions, then show the QR code so pairs continue on their own devices. Teaching with a projector walks through present mode step by step.
• Prediction locks. Prediction questions keep the simulation locked until a student answers, which suits ideas 5, 6 and 8. The Predict–Observe–Explain guide shows how to run the discussion afterward.
• Different numbers per class. On the Share page, create one link per class and pin different starting values, such as a different mass of CaCO₃ in idea 7. Then a number question checks real understanding. Read using simulations for formative assessment to plan what to do with the results.

Remember that each model simplifies. The equilibrium flask uses a simplified K(T) and the rates model doubles the rate every 10 °C. Ask students what a real bench experiment would add.

FAQ

Can these simulations replace chemistry practicals?

No. Use them for what a bench can't do safely or quickly: particle views, molten-salt electrolysis, ten rate runs in ten minutes. Keep real practicals for handling glassware, measuring and observing real substances.

Which idea suits middle school best?

Ideas 1 (build an atom), 3 (states of matter) and 6 (pH scale). They need no equations, and the visual change makes the point.

How do students answer questions without accounts?

Attach a question set to the link. Students type a nickname and answer below the simulation. You see a results table for the link and can export it as CSV.

The equilibrium idea is too hard for my class. What should I use instead?

Use the pH scale (idea 6) or the reactants and leftovers simulation (idea 9). Both build the habit of linking particles to measurements, which equilibrium later relies on.