Chemistry is a logical science. You can master the essential concepts yourself. You can study these concepts in any order, but it's probably best to start from the top and work your way down, since many concepts build on understanding units, conversion and how atoms and molecules interact.
Introduction to Chemistry: Learn about what chemistry is, what chemists do, and why you would want to study this science.
Units & Measurements: Get a handle on the metric system and the commom units used in chemistry.
The Scientific Method: Scientists, including chemists, are systematic about the way they study the world. Find out how to use the scientific method to collect data and design experiments.
The Elements: Elements are a basic building block of matter. Learn what an element is and get facts for them.
The Periodic Table: The Periodic Table is a way elements can be organized, based on their similar properties. Find out what that table is, how it was designed, and how you can use it to make your study of chemistry much easier.
Atoms and Ions: Atoms are single units of an element. Ions can be made up of one or more types of elements and carry an electrical charge. Learn about the parts of an atom and how to identify the different types of ions.
Molecules, Compounds, & Moles: Atoms can be joined together to make molecules and compounds. A mole is a useful way of measuring an amount of atoms or larger components of matter. Define these terms and learn how to perform calculations to express quantities.
Chemical Formulas: Atoms and ions don't bond together randomly. Find out how to predict how many of one type of atom or ion will combine with others. Learn to name compounds.
Chemical Reactions & Equations: Just as atoms and ions combine in very specific ways, molecules and compounds react with each other in definite quantities. Learn how to tell whether or not a reaction can occur and what the products of a reaction will be. Write balanced chemical equations to describe reactions.
Thermochemistry: Chemistry is the study of both matter and energy. Once you learn to balance the atoms and charge in a chemical reaction, you can examine the energy of the reaction as well.
Electronic Structure: Electrons are found in regions around the nucleus of an atom. Learning about the structure of the electron shell or electron cloud is important for understanding how atoms and ions will form bonds.
Chemical Bonds: The atoms in a molecule or compound are attracted and repelled with respect to each other in ways that determine the types of bonds they can form.
Molecular Structure: Once you understand the types of bonds that can be formed between components in a substance, you can begin to predict and understand how molecules are formed and the shapes they take.
Liquids & Gases: Liquids and gases are phases of matter with properties distinctly different from the solid form. Collectively, liquids and solids are termed fluids. The study of fluids and how they interact is important for understanding the properties of matter and predicting the ways in which that matter can react.
Rates of Reaction: Several factors affect how quickly and completely a reaction proceeds. Learn about these factors and how to calculate the speed at which a reaction can occur.
Acids & Bases: There are several ways to define acids and bases. One way is to look at hydrogen ion concentration. No matter which method you choose, these categories of chemicals participate in some very important reactions. Learn about acids, bases, and pH.
Oxidation & Reduction: Oxidation and reduction reactions go hand in hand, which is why they are also called redox reactions. Acids and bases may be thought of as reactions involving hydrogen, or protons, while redox reactions tend to be concerned with electron gain and loss.
Nuclear Reactions: Most chemical reactions involve exchanges of electrons or atoms. Nuclear reactions are concerned with what happens inside the nucleus of an atom. This includes radioactive decay, fission, and fusion.