Practice Activities
Each activity goes with a lesson on zornscience.org. No login needed, and nothing you enter leaves your device.
Atoms, ions and bonding
Start with the periodic table, then predict ion charges and build Lewis structures.
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Reference
Periodic Table
Look up any element, and color the table by atomic radius, electronegativity or ionization energy to see the trends.
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Periodic Trends
Periodic Trends Practice
Compare two elements and use the trend to decide which has the larger radius or the higher electronegativity or ionization energy.
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Ionic Bonding
Predicting Ion Charge Trainer
Find valence electrons, decide what changes, and check your reasoning with hints and feedback.
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Ionic Bonding
Polyatomic Ion Trainer
Race the five-minute clock to recall polyatomic ion names, formulas and charges. Revisit missed questions and review your results.
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Covalent Bonding
Lewis Structure and VSEPR Builder
Count valence electrons, build each Lewis structure, then predict its shape, bond angle and polarity.
Reactions and stoichiometry
Write and balance reactions, including redox, then follow the moles from reactants to products.
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Chemical Reactions
Ionic Reaction Builder
Choose synthesis, decomposition, single replacement, or double replacement, then build products, balance equations, and review your practice.
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Oxidation and Reduction
Redox Half-Reaction Balancer Coach
Split a redox reaction, balance atoms and charge, equalize electrons, and cancel species one step at a time. Practice in acidic or basic media with feedback before each step unlocks.
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Stoichiometry
Stoichiometry Coach
Build conversion factors, watch the units cancel, and solve grams and moles problems with hints and feedback.
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Stoichiometry
Limiting Reactant Visualizer
Pick starting moles of two reactants, predict which runs out, and watch the molecules pair up into products. The excess is left stranded with nothing to react with.
Chemistry labs
Virtual lab benches for gases, solutions, acids and bases, and reaction rates.
Chemical bonding
Chemical Bonding Lab
Investigate four unknown solids with realistic lab equipment. Compare appearance, conductivity, melting, solubility in water and cyclohexane, and malleability to infer bonding types.
Properties of elements
Metals, Nonmetals & Metalloids Lab
Investigate three unknown solids with a watch glass, mortar and pestle, conductivity tester, and dilute hydrochloric acid. Use physical and chemical evidence to classify each sample.
Reaction kinetics
Iodine Clock Lab
Measure and mix two clear solutions on a realistic lab bench. Explore concentration and temperature, watch the sudden blue endpoint, and try a 20-second challenge.
Net ionic equations
Net Ionic Reactions Lab
Mix ten pairs of reagents in realistic glassware. Observe precipitates, a metal displacement reaction, and mixtures with no visible reaction.
Atomic emission
Virtual Flame Test Lab
Click eight known metal salt samples and an unknown to compare their characteristic flame colors in a Bunsen burner.
Analytical chemistry
Gravimetric Analysis
Identify an unknown carbonate with a realistic lab bench. Precipitate, filter, wash, and dry calcium carbonate to constant mass.
Equilibrium
Equilibrium Sandbox
Stress a reversible reaction with concentration, volume and temperature changes. Compare Kc and Qc on a live concentration graph.
AP Chemistry · Equilibrium
Equilibrium Constant Lab
Write K expressions, compare Q with K to predict the shift, solve ICE tables, and explore molar solubility and the common-ion effect with Ksp.
Thermodynamics
Calorimetry & Enthalpy Lab
Drop a heated metal into water or mix acid and base. Follow temperature changes and calculate specific heat or reaction enthalpy.
Thermochemistry
Reaction Energy Lab
Build energy diagrams, explore heating and cooling curves, and calculate reaction enthalpy with stoichiometry, bonds, formation data and Hess's law.
Thermodynamics
Free Energy Lab
Predict entropy changes, explore Gibbs free energy and temperature, link ΔG° with K, and compare kinetic control, dissolving and coupled reactions.
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AP Chemistry · Electrochemistry
Galvanic & Electrolytic Cell Builder
Build metal half-cells, connect a salt bridge and voltmeter, follow electron flow, and calculate standard cell potentials. Apply power to drive the reverse reaction.
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Beer's Law
Beer's Law Spectrophotometer Lab
Zero a spectrophotometer, measure standards to build a calibration curve, then measure a random unknown and calculate its concentration from your line.
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Solutions
Solutions Lab
Weigh a solute and fill a volumetric flask to the line, dilute a stock solution with a pipet, and read solubility curves to tell unsaturated, saturated and supersaturated solutions apart.
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Gases
Gas Laws Sandbox
Explore Boyle’s, Charles’s, Gay-Lussac’s and Avogadro’s laws with locked variables, moving particles and a live graph. Switch between English and Spanish.
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AP Chemistry · Gases
Gas Laws and KMT Lab
Move a piston, heat and add gas, and watch particles hit the walls. Graph the gas laws, compare speed distributions, mix gases and see when real gases stop acting ideal.
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AP Chemistry · Acids and Bases
pH & Buffer Lab
Explore pH, build conjugate pairs, and add acid or base to water and a buffer. Compare buffer capacity with a live graph and downloadable data.
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AP Chemistry · Acids and Bases
Virtual Titration Simulator
Pick an analyte, a titrant and an indicator, then add titrant drop by drop and watch the pH curve grow. Find the equivalence point, and read the pKa at the half-equivalence point.
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AP Chemistry · Kinetics
Kinetics and Collision Theory Sandbox
Watch A and B bounce around a box and react only when they hit hard enough. Change the temperature, the concentration and the activation energy, add a catalyst, and see the concentration graph respond.
Biology labs
Explore photosynthesis and respiration with evidence from a virtual experiment.
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Photosynthesis
Leaf Disk Lab
Float spinach leaf disks to compare light color, brightness, temperature and bicarbonate. Use your data to explain the rate of photosynthesis.
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Populations
Population Sampling Lab
Estimate hidden plant and fish populations with quadrats and mark and recapture. Compare sample sizes, random placement and sampling bias.
Physics
Motion, forces, circuits and optics you can explore with virtual lab equipment.
Electromagnetic Induction
Faraday’s Law · Magnet Drop
Drop a neodymium magnet through copper, reveal eddy currents and induced magnetic fields, and compare intact copper, slotted copper and plastic.
Electric Fields
Equipotential & Electric Field Mapping
Arrange point charges and explore their voltage with a virtual probe, smooth equipotential lines and electric field vectors.
Waves and Resonance
Standing Waves on a String
Tune a mechanical oscillator to create harmonics, change string tension, and use a synchronized strobe and ruler to measure node spacing.
Optics
Snell’s Law & Refraction
Aim a laser through optical blocks, measure angles with a snapping protractor, and explore water, diamond and total internal reflection.
Forces and oscillations
Hooke’s Law & Harmonic Motion
Load a realistic spring with slotted masses, measure extension with a ruler, and explore oscillations with pause, slow motion, and a live position graph.
Oscillations and Energy
The Simple Pendulum
Release a brass pendulum bob, explore mass, length and gravity, and watch kinetic and potential energy exchange on Earth, the Moon and Jupiter.
Forces and Friction
Inclined Plane & Friction
Raise a wooden ramp until the block slips. Explore static and kinetic friction with realistic apparatus and a live free body diagram.
Conservation of Momentum
Collision Carts
Collide realistic dynamics carts on a low-friction track. Switch between elastic and inelastic collisions, adjust masses and velocities, and reveal live velocity and momentum vectors.
Newton’s Second Law
The Atwood Machine
Release two brass masses over an ideal pulley. Explore Newton’s second law with adjustable masses and live force and acceleration vectors.
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Linear Motion
Physics Graphing Lab
Run a cart along a track and watch its position, velocity and acceleration graphs grow together. Sketch your prediction first, then compare it with the model.
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2D Dynamics
Projectile Motion Vector Lab
Fire a cannon from any height, angle and speed, and turn on live velocity and acceleration vectors. Watch the horizontal velocity stay the same while the vertical velocity shrinks, flips and grows.
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Electric Circuits
Circuit Builder
Drag batteries, wires, resistors, switches and bulbs onto a board and probe the circuit with a multimeter. Switch between series and parallel and see why the bulbs glow so differently.
Test prep
Review AP Chemistry, build ACT skills, and practice with a scientific calculator.
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AP Chemistry · Unit 1
AP Chemistry Unit 1 Practice
Catch up on topics 1.1 to 1.8 with 48 original questions, instant explanations, and a mixed review.
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AP Chemistry · Unit 2
AP Chemistry Unit 2 Practice
Catch up on topics 2.1 to 2.7 with 42 original questions, instant explanations, and a mixed review.
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AP Chemistry · Unit 3
AP Chemistry Unit 3 Practice
Catch up on topics 3.1 to 3.13 with 78 original questions, instant explanations, and a mixed review.
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AP Chemistry · Unit 4
AP Chemistry Unit 4 Practice
Catch up on topics 4.1 to 4.9 with 54 original questions, instant explanations, and a mixed review.
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AP Chemistry · Unit 5
AP Chemistry Unit 5 Practice
Catch up on topics 5.1 to 5.11 with 66 original questions, instant explanations, and a mixed review.
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AP Chemistry · Unit 6
AP Chemistry Unit 6 Practice
Catch up on topics 6.1 to 6.9 with 54 original questions, instant explanations, and a mixed review.
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AP Chemistry · Unit 7
AP Chemistry Unit 7 Practice
Catch up on topics 7.1 to 7.12 with 72 original questions, instant explanations, and a mixed review.
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AP Chemistry · Unit 8
AP Chemistry Unit 8 Practice
Catch up on topics 8.1 to 8.11 with 66 original questions, instant explanations, and a mixed review.
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AP Chemistry · Unit 9
AP Chemistry Unit 9 Practice
Catch up on topics 9.1 to 9.11 with 66 original questions, instant explanations, and a mixed review.
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ACT
ACT Practice
Practice questions, one section, or the full ACT with original English, Math, Reading and Science questions, then get estimated scores and tips for the skills you missed.
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Quick ACT practice
ACT Question Generator
Choose English, Math, or Science for a random question from a separate bank of 1,200 original ACT-style questions. Reveal the answer and explanation whenever you need help.
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Calculator skills
Scientific Calculator Practice
Learn a familiar scientific calculator keypad with fractions, powers, roots, trigonometry and six guided exercises. Build calculator confidence before test day.
Quantitative skills
Practice the math skills every science class uses, with new numbers in every set.
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Numbers
Scientific Notation Practice
Write big and small numbers in scientific notation and back in standard notation, and read what the exponent says.
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Numbers
Significant Figures Practice
Count significant figures, round, and use the rules for multiplying, dividing, adding and subtracting.
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Units
Metric Prefixes Practice
Learn what each prefix means, from mega to nano, and use the prefix ladder to convert between units.
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Units
Unit Conversions Practice
Choose and set up one conversion factor so the units cancel, and keep the measurement's significant figures.
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Units
Dimensional Analysis Practice
Chain conversion factors, convert rates and densities, and square or cube factors for area and volume.
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Ratios and Percents
Ratios and Proportions Practice
Write and simplify ratios, solve proportions, and use mole ratios from balanced equations.
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Ratios and Percents
Percents Practice
Change percents to decimals, find parts and percents of a whole, and work out percent composition and percent yield.
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Ratios and Percents
Percent Error and Percent Change Practice
Find percent error and percent change, keep the right sign, and put the right value on the bottom.
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Equations
Reading Formulas Practice
Read formulas as sentences, tell variables from constants, and find changes with Δ as final minus initial.
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Equations
Rearranging Equations Practice
Solve formulas for one variable, undo steps in reverse order, and calculate with the rearranged formula.
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Equations
Substituting with Units Practice
Substitute values with their units, convert to kg, m and s first, and check the unit of every answer.
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Graphs and Change
Direct and Inverse Relationships Practice
Classify data tables and graph shapes, use the ratio and product tests, and predict new values.
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Advanced Tools
Exponents and Logarithms Practice
Use the exponent rules, work in scientific notation, find logs of powers of ten, and go between pH and hydrogen ion concentration.
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Advanced Tools
Trigonometry Basics Practice
Name the sides of a right triangle, use SOH CAH TOA, and find missing sides and angles.
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Advanced Tools
Vectors Practice
Tell scalars from vectors, add vectors tip to tail, and find components.
Lab tools
Work with your own measurements and make clear graphs for your lab write-ups.
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Reading Graphs
Virtual Lab Graphing Tool
Enter or import your data, make a scatter plot with a linear best-fit line, and download your graph for a lab report. Explore slope, units and R².
For teachers
Activities marked with a completion code end a full round with a code that students can paste into Google Classroom.