Free science and math simulations for teaching STEM topics, including physics, chemistry, biology, and math, from University of Colorado Boulder

Build an atom out of protons, neutrons, and electrons, and see how the element, charge, and mass change. Then play a game to test your ideas!

Explore the states of matter with interactive simulations that show how molecules form solids, liquids, and gases.

Founded in 2002 by Nobel Laureate Carl Wieman, the PhET Interactive Simulations project at the University of Colorado Boulder creates free interactive math and science simulations. PhET …

Explore energy conservation with a virtual skater in different skate parks and see energy graphs.

Build and test circuits with batteries, resistors, light bulbs, and switches. Learn about series and parallel circuits, Ohm's law, and conductors and insulators.

Explore diffusion through interactive simulations by adjusting concentration, temperature, mass, and radius.

Explore how organisms with different traits survive various selection agents within the environment.

Build an atom out of protons, neutrons, and electrons, and see how the element, charge, and mass change.

Explore gravity and orbits with interactive simulations.