What is Chemistry?

All matter, from you to the chair you're sitting in, is made up of atoms: individual particles that have specific properties like mass and charge that result in its ability to react with other molecules. Chemistry is the study of matter; how it behaves, what atoms its made of, how atoms bond together and interact, and changes in their energy. Studying chemistry typically requires keeping track of how many atoms are in a sample and how much they weigh.

Molecular mass and molarity

formula mass, percent composition, and the Mole (ChemLibreTexts article)

molar mass worked example (Khan Academy video)

worked practice problems

Balancing equations

overview+worked examples (ChemLibreTexts article)

More Suggested Reading

Lehniger's Principles of Biochemistry 5th edition (used on amazon $25-$50)