This OER discusses matter, elements, compounds, atoms, and the subatomic particles succinctly. It would be most effective if used as a supplement to a text, another website, some type of multimedia, and/or as a review on the subject. There are additional links and resources to support advance instructions and learning. The idea that students are able to work independently to improve their learning is an advantage to using this OER as an augmentation. It contains an assessment with hidden answers, which supports a check for mastery; it also requires some critical thinking skills.