PhET – Physical Science
PhET provides a suite of free, online simulations in a variety of different science disciplines; they can also be filtered by grade level. Each simulation comes with an introduction to a topic, followed by a game or formative assessment for students to practice their skills.
The chemistry portion of their website offers demonstrations of general chemistry concepts such as the behavior of gases, the polarity of molecules, or how to build a molecule. The physics simulations also cover a variety of general physical science topics such as Newtonian physics, waves, and gravity. These activities are great for HSE (high school equivalency) students interested in biological or physical sciences.
A Teaching Resources link can be found underneath each PhET simulation. This link provides lesson plans and student worksheets for each PhET activity. These are great starting places for teachers interested in adapting these exercises for their classroom. There is also an Activities section with teacher-submitted activities. You will need to sign up for a free account to view these resources.