What happens to a population when its environment changes? How do cells control which proteins they make? Why do some materials warm up faster than others?
Students learn science best when they can find out for themselves. That’s why Khan Academy Science is partnering with PhET Interactive Simulations at the University of Colorado Boulder to bring PhET’s free, research-based simulations directly into Khan Academy. Students can now run virtual investigations, collect data, and test their ideas right inside the articles and exercises they already use.
What is PhET Interactive Simulations?
Founded in 2002 by Nobel laureate Carl Wieman, PhET creates free, interactive math and science simulations used by teachers and students around the world. Every PhET sim is grounded in education research and refined through classroom testing, including student interviews and observation of real classroom use.
PhET sims are built to “make the invisible visible.” Students click, drag, and adjust sliders, then get immediate feedback on what changed. That makes it possible to explore cause and effect in ways that are hard to see in a textbook or a lab.
Khan Academy’s videos, articles, and practice already help students build a strong conceptual foundation. Pairing them with PhET simulations gives students something more: the chance to do science instead of just reading about it.
How PhET science simulations work on Khan Academy
You’ll find embedded PhET simulations in two types of learning experiences on Khan Academy:
- Interactive articles: Students build understanding of a concept or conduct virtual investigations, collecting and analyzing data to discover scientific relationships for themselves. In Learn and try: Period of spring-mass oscillators, for example, AP Physics C students use PhET’s Masses and Springs sim to figure out which variables affect how fast a spring oscillates.
- Simulation-based exercises: Students explore a PhET simulation as they work through practice questions anchored in a relevant, real-world context. For example, in PhET simulation: Exploring gene expression, students investigate how GFP-expressing bacteria glow under UV light.
- Interactive articles: Guided investigations give students opportunities to manipulate variables, collect and analyze data, and build understanding step by step.
Every simulation experience is:
- Phenomenon-based: Each set of questions is anchored in a relevant, engaging real-world context.
- Standards-aligned: Activities are aligned to the relevant NGSS, TEKS, or AP standards.
- Connected to the rest of the course: Sims reinforce the concepts students learn in Khan Academy’s videos, articles, and exercises.
How teachers can use PhET simulations in science lessons
Working with PhET simulations on Khan Academy gives students opportunities to use models, plan investigations, analyze data, and construct explanations. They can also explore crosscutting concepts such as cause and effect and patterns as they connect changes in a model to the outcomes they observe.
Virtual investigations make room for this kind of inquiry even when lab equipment, materials, or class time are limited. You can use PhET simulations on Khan Academy to do the following:
- Explore together: Work through an interactive article as a class, using its guided questions to prompt discussion.
- Support partner investigations: Have students follow the investigation instructions in pairs, comparing observations and discussing their answers.
- Reinforce learning: Assign a simulation-based article or exercise so students can apply concepts with built-in guidance.
- Differentiate practice: Select articles or exercises that offer students structured support as they revisit challenging concepts or explore further.
Where to find free PhET science simulations
PhET-based articles and exercises are free and available now on Khan Academy. Find them within relevant course units or look for a course’s “Explore [subject] through simulations” unit, such as Explore biology through simulations.
Choose a science course below to find an interactive article or simulation-based exercise:
Middle school biology
- PhET simulation: Explore natural selection (interactive article)
- PhET challenge: Natural selection (exercise)
Middle school Earth and space science
- PhET simulation: Explore climate change (interactive article)
- PhET challenge: Explore climate change (exercise)
- Learn and try: Gravity and the solar system (interactive article)
Middle school chemistry
- Learn and try: Heat capacity (interactive article)
- PhET challenge: Heat capacity (exercise)
- Learn and try: Temperature (interactive article)
- Learn and try: States of matter and phase changes (interactive article)
- Learn and try: Balancing chemical equations (interactive article)
Middle school physics
- Learn and try: Conservation of energy (interactive article)
- PhET challenge: Conservation of energy (exercise)
- Learn and try: Connecting motion and forces (interactive article)
- Learn and try: Gravitational force (interactive article)
- Learn and try: Electric and magnetic forces (interactive article)
- Learn and try: Wave properties (interactive article)
High school biology
- PhET simulation: Exploring gene expression (exercise)
- PhET simulation: Exploring natural selection (exercise)
- PhET simulation: Exploring the greenhouse effect (exercise)
High school chemistry
- Learn and try: Atomic structure (interactive article)
- Learn and try: Atomic spectra (interactive article)
High school physics
- Learn and try: Stars (interactive article)
AP Biology
- PhET simulation: Exploring diffusion (exercise)
- PhET simulation: Exploring action potentials (exercise)
- PhET simulation: Exploring gene expression (exercise)
- PhET simulation: Exploring Hardy-Weinberg equilibrium (exercise)
AP Physics
- Learn and try: Projectile motion (interactive article)
- Learn and try: Collisions (interactive article)
- Learn and try: Period of spring-mass oscillators (interactive article)
- Learn and try: Period of simple pendulums (interactive article)
- Learn and try: Combinations of springs (interactive article)
Bring a virtual investigation into your next lesson and give students a chance to turn curiosity into understanding. With PhET simulations and Khan Academy’s built-in guidance, they’ll have support as they ask questions, test ideas, and make sense of what they discover.
