Notice to Chemistry Teachers:

Over the next year we will be doing a significant Concept Builder upgrade from the current version (Version 2.0 - 2.2, depending on the Concept Builder) to a Version 3.0. The conversion will occur in two steps, with the first step being a Version 2.5 upgrade and the second step being a Version 3.0 upgrade. "Screenshot validation" (which we have never regarded to have much value in terms of validation) is not possible in Version 2.2 and won't be possible in any future version.  Nonetheless, Version 2.5 and Version 3.0 will both be more "Guest-friendly" than Version 2.2. But neither version will include progress tracking for Guest users. All upgrades will provide significant improvements to the Task Tracker experience with a Concept Builder. For those planning budgets for 2024-25 school year, a low-cost Task Tracker subscription would be a good investment. Consider adding The Calculator Pad to it if your budget permits. Contact us if you need more information.


What?!? Chemistry? At The Physics Classroom?

Yes. Why not? We're not breaking any laws ... it's perfectly legal. The Concept Builders you see below are  interactive questioning modules that present learners with carefully crafted questions that target various aspects of a concept. If you're a frequent visitor to our website, you likely have used some of our Physics Concept Builders. Each Concept Builder focuses the learner's attention upon a discrete learning outcome. Questions target that outcome from a variety of angles using multiple difficulty levels or varying activities. If you're a chemistry teacher visiting our website for the first time, then welcome! We invite you to give one of our Chemistry Concept Builders a try and let us know what you think. 


Chemistry Topics to Explore

Quick Links


Lab Equipment, Procedures, and Safety

Lab Equipment
Learning Goal: To identify the name of basic lab equipment and to associate the equipment with the purpose it serves within the lab.

Lab Safety
Coming soon - late July, 2024.

Lab Procedures

Coming soon - late July, 2024.



Units and Measurement

Measurement and Numbers
Learning Goal: To identify common units of measurement, to read an instrument to the proper number of significant digits, and to convert between standard and scientific notation.

Significant Digits and Measurement
Learning Goal: To understand the concept of significant digits and to use such understanding to make and process such measurements made from lab equipment.

Metric System
Learning Goal: To generate a comfort with the use of the metric system in order to convert simple quantities and compare given quantities.

Metric Estimation
Learning Goal: To use an understanding of metric units of length, mass, and volume to identify a best estimate of such quantities for a variety of common objects.

Metric Conversions
Learning Goal: To use an understanding of metric units and their Greek prefixes to perform conversions between a variety of metric units.



Properties of Matter

Classification of Matter
Learning Goal: To identify samples of matter as being pure substances or mixtures (homogenous or heterogeneous) and to distinguish between elements and compounds.

Name That Element
Learning Goal: To express a comfort with the organization of the periodic table, including concepts related to family names, periods, groups, metals, nonmetals, metalloids, atomic number, and atomic mass.

Chemical vs. Physical Properties
Learning Goal: To identify a stated property as being either a chemical or a physical property.

Density Ranking Tasks 
Learning Goal: To rank the density of three samples of matter based on information about the massiveness of its particles and the amount of space they take up.

Metals, Nonmetals, and Metalloids 
Learning Goal: To identify the difference between metals, nonmetals, and metalloids and to be able to place an element into one of these categories.

Particles .. Words .. Formulas 
Learning Goal: To associate the particle representation of a sample of matter with the proper verbal description and formulas.



Chemical Reactions

Names to Formulas 1
Learning Goal: To use an understanding of formula writing to identify incorrectly written formulas.  (Includes binary ionic compounds only.)

Names to Formulas 2
Learning Goal: To use an understanding of formula writing to identify incorrectly written formulas.  (Includes binary molecular compounds, binary ionic compounds, and compounds containing polyatomic ions.)

Formulas and Atom Counting
Learning Goal: To identify the number of atoms of each element represented by a set of simple or complex formulas.

Balancing Chemical Equations
Learning Goal: To be able to use coefficients and an atom count to balance a chemical equation. 

Chemical Reaction Types
Learning Goal: To be able to categorize chemical reactions based on their reaction type - such as synthesis, decomposition, combustion, single replacement, and double replacement.

Writing Balanced Chemical Equations
Learning Goal: To combine an understanding of reaction types, formula writing, and equation balancing in order to write a balanced chemical equation. 

Precipitation Reactions
Learning Goal: To predict the precipitate that is produced when two aqueous solutions of ionic compounds are mixed and to represent the precipitation reaction by a net ionic equation.




Molar Mass
Learning Goal: To determine the molar mass if given the chemical formula of a compound.

Mole Conversions
Learning Goal: To mathematically relate the the number of moles of a compound to the number of molecules and to the mass in grams.

Elemental Measures (a.k.a. Stoikheion-metry)
Learning Goal:  To calculate the number of atoms and the mass in grams of each element involved in the reaction on the reactant and the product side so as to show that atoms, and therefore mass, are conserved in a chemical reaction.

Stoichiometry: Relationships
Learning Goal: To use the coefficients of a balanced chemical equation and the molar masses of reactants and products to relate the quantities of reactants and products involved in a reaction.

Stoichiometry Law Breakers
Learning Goal: To identify conversion factors that are capable and incapable of converting from a given quantity to an unknown quantity in a stoichiometry problem.

Mass Stoichiometry
Learning Goal: To relate the mass of a reactant to the mass of other reactants and products in a balanced chemical equation.

Limiting Reactants
Learning Goal: To analyze the stoichiometry of a chemical reaction involving a limiting and excess reactant.



Atomic and Molecular Models

Atomic Models
Learning Goal:  To identify the connection between experimental findings, conclusions, and models that are associated with atomic structure.

Subatomic Particles
Learning Goal: To determine the atomic number, mass number, # of protons, # of neutrons, and the # of electrons for an atom or an ion of an element from an isotope symbol.

Learning Goal: To demonstrate understanding of the composition of an atom by constructing the isotopic symbol from information regarding the number of protons, neutrons, and electrons.

Line Spectra
Learning Goal:  To relate the color of lines in a line spectra of an element to the energy level transitions that are occurring.

Quantum Mechanics
Learning Goal:  To identify the meaning of the four quantum numbers, the rules governing allowed and non-allowed quantum number values, and the characteristics of atomic orbitals.

Complete Electron Configurations
Learning Goal: To identify the complete electron configuration for a neutral atom or of an ion of any given element.

Periodic Table Battleship
Learning Goal: To associate an electron configuration with a location of an element on the periodic table.

Periodic Trends
Learning Goal: To order elements based on the values of periodic properties such as atomic radius, ionization energy, and electronegativity.

Ionic Bonding
Learning Goal: To identify the types of elements that undergo ionic bonding and to be able to describe the process that takes place when two elements form ionic bonds.

Bond Polarity
Learning Goal: To use electronegativity values to identify a bond as being polar or non-polar … and if polar, to identify the direction of the dipole moment vector.

Lewis Structures
Learning Goal:  To identify correct and incorrect Lewis electron dot structures when given the formulas of molecular compounds.

Valence Shell Electron Pair Repulsion Theory
Learning Goal:  To identify the Lewis electron dot diagram and the molecular shape of a variety of covalently-bonded molecules.

Molecular Polarity
Learning Goal:  To use electronegativity values, a Lewis structure, and an understanding of molecular shape to identify a molecule as being polar or non-polar.



Thermal Chemistry and Thermodynamics

Measuring the Quantity of Heat
Learning Goal:  To use the equation Q = m•C•∆T to relate the heat released to the surroundings to the mass and temperature change of the surroundings and to the enthalpy change of the system.

Which One Doesn't Belong? - Energy and Chemical Reactions
Learning Goal:  To interpret various representations of a thermochemical reaction and to identify which one is not consistent with the others.

Enthalpy Change
Learning Goal: To use calorimetry data and the amount of reactant to determine the enthalpy change for a stated reaction and to include the energy term on the proper side of a thermochemical equation.

Thermal Stoichiometry
Learning Goal: To use a thermochemical equation to relate the mass and the moles of reactant to the amount of energy released in a combustion reaction.

Hess's Law
Learning Goal: To apply Hess’s Law in order to determine the ∆H of a reaction if given the ∆H of two or more related reactions.

Heat of Formation
Learning Goal: To identify the meaning of heat of formation and to use heats of formation values for reactants and products to determine the enthalpy change of a reaction.

Learning Goal: To compare the entropy of two different states and to identify the entropy change of a process as being either a positive or a negative change.

Spontaneity and Driving Forces
Learning Goal: To use knowledge of the ∆H and ∆S values for a reaction in order to predict whether it is spontaneous or not.

Gibb's Free Energy
Learning Goal: To use the Gibb’s Free Energy equation to calculate a free energy change (∆G) from ∆H and ∆S values at various temperatures and to make judgement regarding the spontaneity of the reaction.



Solids, Liquids, and Gases

States of Matter
Learning Goal:  To describe the three most common states of matter and to describe the state transitions that take place.

Intermolecular Forces
Learning Goal:  To use an understanding of intermolecular forces (IMFs) in order to predict the types of IMFs experienced by a substance and to rank substances in terms of the strength of their IMFs.

Pressure Concepts
Learning Goal:  To be able to explain at the particle level the factors that effect gas pressure, to compare values of pressure expressed in different units, and to use manometer information to determine the pressure of a gas.

Pressure and Temperature
Learning Goal:  To use an understanding of the pressure-temperature relationship in order to predict how the value of pressure changes with changing temperature.

Volume and Temperature
Learning Goal:  To use an understanding of the volume-temperature relationship in order to predict how the value of volume changes with changing temperature.

Pressure and Volume
Learning Goal:  To use an understanding of the pressure-volume relationship in order to predict how the pressure of a gas changes with varying volume.



Acids, Bases, and Solutions

Learning Goal:  To be able to write the equation for the dissociation of an ionic compound in water and to use the equation to determine ion concentrations if given the concentration of the ionic compound. 

Molarity Ranking Tasks
Learning Goal:  To rank the relative molarity of three aqueous solutions based on the amount of solute, the amount of solvent, and the identity of the solute.

Molarity Calculations
Learning Goal:  To use molarity definition to calculate the molarity of a solution from knowledge of the amount of solute (in grams or moles) and the volume of the solution.

Which One Doesn't Belong? - Acid-Base Properties
Learning Goal:  To analyze a variety of properties of acids and bases in order to identify which property is not like the others.

Bronsted-Lowry Model of Acids and Bases
Learning Goal:  To use the Bronsted-Lowry model to determine the products of the dissociation of an acid or a base when dissolved in water.

pH and pOH
Learning Goal:  To mathematically relate the pH, pOH, [H3O+], and [OH-] for aqueous solutions of acids and bases.



Equilibrium and Kinetics

Collision Model of Reaction Rates
Learning Goal:  To identify the variables that affect reaction rate and to explain the effects using the Collision Model of reaction rates.

The Equilibrium Concept
Learning Goal:  To identify the conditions that exist at equilibrium, to comprehend the meaning of he equilibrium concept (K), and to use the K value to predict the direction a reaction proceeds to reach equilibrium.

Equilibrium Constant Expression
Learning Goal:  To use the Law of Mass Action in order to identify the equilibrium constant expression for a given chemical equation.

Equilibrium Calculations
Learning Goal:  To use an equlibrium constant expression to determine the equilibrium constant value or the value of the concentration of a reactant or product at equilibrium.

Equilibrium ICE Tables
Learning Goal:  To learn how to set up an ICE table and then use it to relate initial concentrations of reactants and products to the equilibrium constant.

LeChatelier's Principle
Learning Goal:  To identify the effect that a stress has upon a system that is at equilibrium.





Oxidation States
Learning Goal: To identify the oxidation state of elements in various substances.

Learning Goal:  To use oxidation numbers to determine the elements being oxidized and reduced in an oxidation-reduction reaction and to identify the oxidizing and reducing agents.

Galvanic Cells
Learning Goal:  To create a galvanic cell diagram, identifying the anode and cathode, the direction of electron flow and positive and negative ion flow, and identifying the half equations occurring in each half-cell.

Reduction Potential
Learning Goal:  To interpret a standard reduction potential table in order to make judgements about the strength and capability of oxidizing and reducing agents.

Cell Voltage
Learning Goal:  To use the Reduction Potential Table to determine the cell voltage of a galvanic cell.



Nuclear Chemistry

Nuclear Decay
Learning Goal:  To identify the various forms of nuclear decay and the effect of each upon the atomic number and mass number of an isotope. 

As of this writing (late June, 2024), we have 72 Chemistry Concept Builders. We still have many more planned. 

Additional Chemistry activities can be found in the Calculator Pad and the Science Reasoning Center.

This might be The Physics Classroom, but Chemistry is still a legal operation on this site. So enjoy our Chem Gems.