- Dynamic Periodic TableTablet friendly web app that lets you browse elements; provides properties, data subsets, orbitals, isotopes, compound mixing, compound searching. Copyright by M. Dayah.

- PrepSTEP for Colleges (Learning Express Library)Contains practice tests for: credit by examination; core math, science, and english skills; civil service; ESL (Spanish) skills improvement courses; graduate school entrance; military; teacher certification; and US citizenship. Students must create a free account to take the practice tests.

- Peterson's Test Prep This link opens in a new windowOnline practice tests including entrance exams, certification, and licensing tests. Also provides information on colleges and universities, scholarships, and resumes. List of tests and courses is available here.

- Significant FiguresA quick summary of how to use significant figures to communicate uncertainty in measurements and calculations. From a Chemistry Tutorial from Washington University in St. Louis.
- Kahn Academyâ€”ChemistryCovers the material in a first year introductory high school or college general chemistry course.

- NIST Guide for the use of the International System of Units(Special Publication 811) Includes links to the BIPM SI Brochure (9th edition), the NIST SP 330 2019 version, SP 811 in PDF format, and a poster of SI Base Units Relationships Poster.

- Chemistry math skills review by Dr. Wendy Keeney-KennicuttDr. Kennicutt is a professor at Texas A & M University. This site covers algebraic manipulation, dimensional analysis, significant figures, manipulation of exponents, scientific notation, logarithms, the quadratic equation, and standard deviation.
- Using Google as a calculator and converterHow to use Google for math equations and conversions.

- American Chemical Society Twitter AccountThe American Chemical Society is the worldâ€™s largest scientific society and a leading source of authoritative scientific info.