The Story of Chemistry
Follow our guided path to understand how matter is built, from the atom up to the complex world around us.
Unit I: Fundamentals of Matter & Reactions
Start your journey here. Learn what atoms are, how they were discovered, and the fundamental rules that govern how they connect to form everything you see.
The Atom
Begin by discovering the atom. Follow the timeline of scientific breakthroughs that revealed its structure, from a simple sphere to the modern quantum cloud.
How Atoms Connect
Like people, atoms don't like to be alone. They seek stability by forming relationships—giving, taking, or sharing electrons. This is the story of chemical bonding.
Types of Chemical Reactions
Once atoms are bonded, they can engage in the grand "dance" of chemistry—rearranging partners and forming new substances. Discover the five main types of these reactions.
Unit II: The Library of the Elements
With the fundamentals understood, it's time to explore the complete library of atomic building blocks. The Periodic Table organizes every known element by its properties and structure.
The Periodic Table
Meet the full cast of characters in chemistry. Explore the properties, trends, and secrets of all 118 elements in our fully interactive periodic table.
Metal Groups
Explore the diverse families of metals, from the highly reactive alkali metals to the colorful and versatile transition metals that form the backbone of industry.
Metalloids & Nonmetals
Discover the elements that bridge the gap between metals and nonmetals, and explore the diverse families that form the basis of life and the air we breathe.
Unit III Prerequisite: Drawing Lewis Structures
Before diving into stoichiometry, you must know how to draw Lewis Structures. This skill is essential for understanding molecular geometry and polarity, which influences how reactions occur.
Unit III: Chemical Arithmetic (Stoichiometry)
Now that you've met the elements and know how they react, it's time to learn the "accounting" of chemistry. Stoichiometry is the science of measuring the amounts of substances involved in chemical reactions.
Balancing Chemical Equations
Before you can do any chemical calculation, you must first learn to balance the "recipe." Master the art of ensuring the law of conservation of mass is obeyed in every reaction.
The Mole Concept
Meet chemistry's most important number. The mole is the bridge that connects the microscopic world of atoms to the macroscopic world of grams that we can measure in the lab.
Molar Mass
Learn how to use the periodic table to calculate the mass of one mole of any element or compound—a crucial skill for every chemical calculation you'll ever perform.
Stoichiometric Calculations
This is where it all comes together. Use balanced equations and the mole concept to predict the exact amounts of reactants needed and products formed in a chemical reaction.
Limiting Reactants & Percent Yield
Discover what happens when you don't have perfect amounts of ingredients. Learn to identify the limiting reactant and calculate your actual vs. theoretical yield.
Unit IV: Aqueous Solutions
Most chemistry happens in water. This unit explores the properties of solutions, concentration, and the behavior of acids and bases.
Solutions & Molarity
Learn the language of solutions. Master concentration calculations using Molarity and learn how to perform dilutions with the M₁V₁=M₂V₂ equation.
Solution Stoichiometry (New!)
Apply your stoichiometry skills to reactions in solutions. Use molarity as a conversion factor to predict product amounts and reactant needs.
Acids & Bases
Explore the properties of acids and bases, understand the pH scale, and learn about Brønsted-Lowry theory.
Titrations
Learn the practical lab technique of titration to determine the unknown concentration of a solution with precision. (New!)