Chemistry Notes

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


Matter changes form but not identity in a physical change. A chemical reaction occurs and a new product is formed in a chemical change. (rawpixel)
Identifying chemical and physical changes and learning how to tell them apart can be confusing. Basically, both are changes in the structure of matter. In a physical change, matter changes forms but does not change its chemical identity. In a chemical change, a chemical reaction occurs and a new substance […]

Chemical and Physical Changes of Matter


Protons and electrons stick to each other as much as they can, but kinetic energy and quantum mechanics keep them from holding still.
Protons and electrons are attracted to each other because the positive electric charge of the proton is attracted to the negative charge of the electron. But, if they two particles find each other so attractive, why don’t protons and electrons stick together? Orbits and Waves In a sense, protons and […]

Why Don’t Protons Stick to Electrons?




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