Chemistry Notes

Learn chemistry. Here you will find a collection of chemistry notes, projects, worksheets, and labs.


An electron is a unit of matter with a negative electrical charge. (Anne Helmenstine)
Atoms are made of protons, neutrons, and electrons. Of these three particles, the electron has the smallest mass. Here is the definition of the electron, along with its word origin, history, and interesting facts. Electron Definition An electron is a stable subatomic particle with a negative electrical charge. Each electron […]

What Is an Electron?


A proton is a subatomic particle with a positive charge. It is found in the atomic nucleus. (AG Caesar)
Atoms consist of smaller particles called protons, neutrons, and electrons. Here is the definition of a proton, its electric charge, where it’s found in the atom, and a collection of proton facts. Proton Definition A proton is a subatomic particle with a mass defined as 1 and a charge of […]

What Is a Proton?


Color is a good indicator of purity. Usually, a pure substance is all one color. You can tell this smoke is impure by its color variation. (rawpixel) 1
In chemistry, a pure substance is a material with a constant composition. In other words, it is homogeneous no matter when you sample it. A pure substance consists entirely of one type of atom or compound. It participates predictably in a chemical reaction. Examples of Pure Substances The best examples […]

Examples of Pure Substances




Both organic and inorganic compounds may contain carbon. Organic compounds contain carbon bonded to hydrogen. (Hans Reniers)
The terms “organic” and “inorganic” mean something different in chemistry than when you’re talking about food and produce. Organic and inorganic compounds form the basis for organic chemistry and inorganic chemistry. Organic chemists study organic molecules, their synthesis, and the reactions between them. Inorganic chemists study all other types of […]

Difference Between Organic and Inorganic


Review important chemistry facts before you take the AP chemistry exam. (Stephan Stefancik)
Before you take the AP Chemistry Exam (Advanced Placement Chemistry Exam), it’s helpful to review facts you need to know for the test. These facts are also helpful if you are studying for any other high school or college cumulative chemistry test. About the AP Chemistry Exam You don’t have […]

AP Chemistry Exam – Facts to Know