| Resource | What it adds | Link | |----------|--------------|------| | (interactive e‑books) | Text + embedded videos & simulations | https://www.ck12.org/ | | PhET Interactive Simulations (University of Colorado) | Hands‑on physics/chemistry/biology simulations | https://phet.colorado.edu/ | | Quizlet Sets (free) | Flashcards & self‑quizzing for terms & formulas | Search “AP Chemistry Chapter 5”. | | LibreTexts | Open‑access textbooks with video links | https://libretexts.org/ |