PhET INTERACTIVE SIMULATIONS

Acid-Base Solutions

How do strong and weak acids differ? Use lab tools on your computer to find out! Dip the paper or the probe into solution to measure the pH, or put in the electrodes to measure the conductivity. Then see how concentration and strength affect pH. Can a weak acid solution have the same pH as a strong acid solution?

Area Builder

Create your own shapes using colorful blocks and explore the relationship between perimeter and area. Compare the area and perimeter of two shapes side-by-side. Challenge yourself in the game screen to build shapes or find the area of funky figures. Try to collect lots of stars!

Area Model Algebra

Build rectangles of various sizes and relate multiplication to area. Discover new strategies for multiplying algebraic expressions. Use the game screen to test your multiplication and factoring skills!

Area Model Decimals

Build rectangles of various sizes and relate multiplication to area. Partition a rectangle into smaller areas and discover new strategies for multiplying decimals!

Area Model Introduction

Build rectangles of various sizes and relate multiplication to area. Partition a rectangle into two areas to discover the distributive property.

Area Model Multiplication

Build rectangles of various sizes and relate multiplication to area. Discover new strategies for multiplying large numbers. Use the game screen to test your problem solving strategies!

Arithmetic

Remember your multiplication tables? Practice your multiplication, division, and factoring skills with this exciting game. No calculators allowed!

Atomic Interactions

Explore the interactions between various combinations of two atoms. Observe the total force acting on the atoms or the individual attractive and repulsive forces. Customize the attraction to see how changing the atomic diameter and interaction strength affects the interaction.

Balancing Act

Play with objects on a teeter totter to learn about balance. Test what you've learned by trying the Balance Challenge game.

Balancing Chemical Equations

How do you know if a chemical equation is balanced? What can you change to balance an equation? Play a game to test your ideas!

Balloons and Static Electricity

Grab a balloon to explore concepts of static electricity such as charge transfer, attraction, repulsion, and induced charge.

Beer's Law Lab

“The thicker the glass, the darker the brew, the less the light that passes through.” Make colorful concentrated and dilute solutions and explore how much light they absorb and transmit using a virtual spectrophotometer!

Bending Light

Explore bending of light between two media with different indices of refraction. See how changing from air to water to glass changes the bending angle. Play with prisms of different shapes and make rainbows.

Blackbody Spectrum

How does the blackbody spectrum of the sun compare to visible light? Learn about the blackbody spectrum of Sirius A, the sun, a light bulb, and the earth. Adjust the temperature to see the wavelength and intensity of the spectrum change. View the color of the peak of the spectral curve.

Build a Fraction

Build fractions from shapes and numbers to earn stars in this fractions game or explore in the Fractions Lab. Challenge yourself on any level you like. Try to collect lots of stars!

Build a Molecule

Starting from atoms, see how many molecules you can build. Collect your molecules and view them in 3D!

Build an Atom

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!

Capacitor Lab: Basics

Explore how a capacitor works! Change the size of the plates and the distance between them. Change the voltage and see charges build up on the plates. View the electric field, and measure the voltage. Connect a charged capacitor to a light bulb and observe a discharging RC circuit.

Charges and Fields

Arrange positive and negative charges in space and view the resulting electric field and electrostatic potential. Plot equipotential lines and discover their relationship to the electric field. Create models of dipoles, capacitors, and more!

Circuit Construction Kit: DC

Experiment with an electronics kit! Build circuits with batteries, resistors, ideal and non-Ohmic light bulbs, fuses, and switches. Determine if everyday objects are conductors or insulators, and take measurements with an ammeter and voltmeter. View the circuit as a schematic diagram, or switch to a lifelike view.

Circuit Construction Kit: DC - Virtual Lab

Do you like Circuit Construction Kit: DC, but want to use only in-line ammeters? This is the sim for you! Experiment with an electronics kit. Build circuits with batteries, resistors, ideal and non-Ohmic light bulbs, fuses, and switches. Determine if everyday objects are conductors or insulators, and take measurements with a lifelike ammeter and voltmeter. View the circuit as a schematic diagram, or switch to a lifelike view.

Collision Lab

Investigate simple collisions in 1D and more complex collisions in 2D. Experiment with the number of balls, masses, and initial conditions. Vary the elasticity and see how the total momentum and kinetic energy change during collisions.

Color Vision

Make a whole rainbow by mixing red, green, and blue light. Change the wavelength of a monochromatic beam or filter white light. View the light as a solid beam, or see the individual photons.

Concentration

Watch your solution change color as you mix chemicals with water. Then check molarity with the concentration meter. What are all the ways you can change the concentration of your solution? Switch solutes to compare different chemicals and find out how concentrated you can go before you hit saturation!

Coulomb's Law

Visualize the electrostatic force that two charges exert on each other. Observe how changing the sign and magnitude of the charges and the distance between them affects the electrostatic force.

Curve Fitting

Drag data points and their error bars and watch the best-fit polynomial curve update instantly. You choose the type of fit: linear, quadratic, or cubic. The reduced chi-square statistic shows you when the fit is good. Or you can try to find the best fit by manually adjusting fit parameters.

Diffusion

Mix two gases to explore diffusion! Experiment with concentration, temperature, mass, and radius and determine how these factors affect the rate of diffusion.

Energy Forms and Changes

Explore how heating and cooling iron, brick, water, and olive oil adds or removes energy. See how energy is transferred between objects. Build your own system, with energy sources, changers, and users. Track and visualize how energy flows and changes through your system.

Energy Skate Park

Learn about the conservation of energy at the skate park! Build tracks, ramps, and jumps for the skater. View the skater's kinetic energy, potential energy, and thermal energy as they move along the track. Measure the speed and adjust the friction, gravity, and mass.

Energy Skate Park: Basics

Learn about conservation of energy with a skater gal! Explore different tracks and view the kinetic energy, potential energy and friction as she moves. Build your own tracks, ramps, and jumps for the skater.

Equality Explorer

Explore what it means for a mathematical statement to be balanced or unbalanced by interacting with objects on a balance. Discover the rules for keeping it balanced. Collect stars by playing the game!

Equality Explorer: Basics

Explore what it means for a mathematical statement to be balanced or unbalanced by interacting with objects on a balance. Find all the ways to balance cats and dogs or apples and oranges.

Equality Explorer: Two Variables

Explore what it means for a mathematical statement to be balanced or unbalanced by interacting with integers and variables on a balance. Find multiple ways to balance x and y to build a system of equations.

Expression Exchange

Build coin expressions, then exchange them for variable expressions. Simplify and evaluate expressions until you are ready to test your understanding of equivalent expressions in the game!

Faraday's Law

Investigate Faraday's law and how a changing magnetic flux can produce a flow of electricity!

Forces and Motion: Basics

Explore the forces at work when pulling against a cart, and pushing a refrigerator, crate, or person. Create an applied force and see how it makes objects move. Change friction and see how it affects the motion of objects.

Fraction Matcher

Match shapes and numbers to earn stars in this fractions game. Challenge yourself on any level you like. Try to collect lots of stars!

Fractions: Equality

Build equivalent fractions with different denominators. Match shapes and numbers to earn stars in the game. Challenge yourself on any level you like. Try to collect lots of stars!

Fractions: Intro

Explore fractions while you help yourself to 1/3 of a chocolate cake and wash it down with 1/2 a glass of water! Create your own fractions using fun interactive objects. Match shapes and numbers to earn stars in the fractions game. Challenge yourself on any level you like. Try to collect lots of stars!

Fractions: Mixed Numbers

Explore fractions while you help yourself to 1 and 1/2 chocolate cakes and wash it down with 1/3 a glass of water! Create your own fractions using fun interactive objects. Match shapes and numbers to earn stars in the mixed number game. Challenge yourself on any level you like. Try to collect lots of stars!

Friction

Move the Chemistry book and observe what happens.

Function Builder

Play with functions while you ponder Art History. Explore geometric transformations and transform your thinking about linear functions, then have fun figuring out the mystery functions!

Function Builder: Basics

Play with functions while you ponder Art History. Look for patterns, then apply what you learned on the Mystery screen!

Gas Properties

Pump gas molecules to a box and see what happens as you change the volume, add or remove heat, and more. Measure the temperature and pressure, and discover how the properties of the gas vary in relation to each other. Examine kinetic energy and speed histograms for light and heavy particles. Explore diffusion and determine how concentration, temperature, mass, and radius affect the rate of diffusion.

Gases Intro

Pump gas molecules to a box and see what happens as you change the volume, add or remove heat, and more. Measure the temperature and pressure, and discover how the properties of the gas vary in relation to each other.

Gene Expression Essentials

Express yourself through your genes! See if you can generate and collect three types of protein, then move on to explore the factors that affect protein synthesis in a cell.

Graphing Lines

Explore the world of lines. Investigate the relationships between linear equations, slope, and graphs of lines. Challenge yourself in the line game!

Graphing Quadratics

Discover how changing coefficients changes the shape of a curve. View the graphs of individual terms (e.g. y=bx) to see how they add to generate the polynomial curve. Generate definitions for vertex, roots, and axis of symmetry. Compare different forms of a quadratic function. Define a curve by its focus and directrix.

Graphing Slope-Intercept

Explore slope-intercept form of a line. Connect the slope and y-intercept to the equation of the line. Challenge yourself in the line game!

Gravity Force Lab

Visualize the gravitational force that two objects exert on each other. Adjust properties of the objects to see how changing the properties affects the gravitational attraction.

Gravity Force Lab: Basics

Visualize the gravitational force that two objects exert on each other. Discover the factors that affect gravitational attraction, and determine how adjusting these factors will change the gravitational force.

Gravity and Orbits

Move the sun, earth, moon and space station to see how it affects their gravitational forces and orbital paths. Visualize the sizes and distances between different heavenly bodies, and turn off gravity to see what would happen without it!

Hooke's Law

Stretch and compress springs to explore the relationships between force, spring constant, displacement, and potential energy! Investigate what happens when two springs are connected in series and parallel.

Isotopes and Atomic Mass

Are all atoms of an element the same? How can you tell one isotope from another? Use the sim to learn about isotopes and how abundance relates to the average atomic mass of an element.

John Travoltage

Play with John’s foot and arm to explore when he gets a shock!

Least-Squares Regression

Create your own scatter plot or use real-world data and try to fit a line to it! Explore how individual data points affect the correlation coefficient and best-fit line.

Make a Ten

Add numbers by making tens. Break apart and combine numbers while focusing on place value. Use the adding screen to add any two numbers. Use the game screen to apply your make-a-ten strategies!

Masses and Springs

Hang masses from springs and adjust the spring constant and damping. Transport the lab to different planets, or slow down time. Observe the forces and energy in the system in real-time, and measure the period using the stopwatch.

Masses and Springs: Basics

Hang masses from springs and discover how they stretch and oscillate. Compare two mass-spring systems, and experiment with spring constant. Transport the lab to different planets, slow down time, and observe the velocity and acceleration throughout the oscillation.

Molarity

What determines the concentration of a solution? Learn about the relationships between moles, liters, and molarity by adjusting the amount of solute and solution volume. Change solutes to compare different chemical compounds in water.

Molecule Polarity

When is a molecule polar? Change the electronegativity of atoms in a molecule to see how it affects polarity. See how the molecule behaves in an electric field. Change the bond angle to see how shape affects polarity.

Molecule Shapes

Explore molecule shapes by building molecules in 3D! How does molecule shape change with different numbers of bonds and electron pairs? Find out by adding single, double or triple bonds and lone pairs to the central atom. Then, compare the model to real molecules!

Molecule Shapes: Basics

Explore molecule shapes by building molecules in 3D! Find out how a molecule's shape changes as you add atoms to a molecule.

Molecules and Light

Turn light source on to explore. Observe what happens in the observation window as you set up different combinations of light source and molecule. Note this simulation is the first to support our pan and zoom feature, so zoom in for a closer look, if you need to.

Natural Selection

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

Neuron

Stimulate a neuron and monitor what happens. Pause, rewind, and move forward in time in order to observe the ions as they move across the neuron membrane.

Number Line: Integers

What do elevation, account balances, and temperature have in common? They can all be represented on a number line. Compare integers on a number line and in an inequality statement. Discover the meaning of absolute value.

Number Line: Operations

Explore operations with integers using an authentic context of net worth, then generalize with a number line. Experiment with adding and subtracting both positives and negatives, and make predictions about whether the total will be positive or negative.

Ohm's Law

See how the equation form of Ohm's law relates to a simple circuit. Adjust the voltage and resistance, and see the current change according to Ohm's law.

Pendulum Lab

Play with one or two pendulums and discover how the period of a simple pendulum depends on the length of the string, the mass of the pendulum bob, the strength of gravity, and the amplitude of the swing. Observe the energy in the system in real-time, and vary the amount of friction. Measure the period using the stopwatch or period timer. Use the pendulum to find the value of g on Planet X. Notice the anharmonic behavior at large amplitude.

Plinko Probability

Drop balls through a triangular grid of pegs and see them accumulate in containers. Switch to a histogram view and compare the distribution of balls to an ideal binomial distribution. Adjust the binary probability and develop your knowledge of statistics!

Projectile Motion

Blast a car out of a cannon, and challenge yourself to hit a target! Learn about projectile motion by firing various objects. Set parameters such as angle, initial speed, and mass. Explore vector representations, and add air resistance to investigate the factors that influence drag.

Proportion Playground

Play with ratios and proportions by designing a necklace, throwing paint balloons, playing billiards, or shopping for apples! Make predictions about proportions before they are revealed.

Ratio and Proportion

Play with the left and right hands in different ways, and explore ratio and proportion. Start on the Discover screen to find each challenge ratio by moving the hands. Then, on the Create screen, set your own challenge ratios. Once you've found a challenge ratio, try to move both hands while maintaining the challenge ratio through proportional reasoning.

Reactants, Products and Leftovers

Create your own sandwich and then see how many sandwiches you can make with different amounts of ingredients. Do the same with chemical reactions. See how many products you can make with different amounts of reactants. Play a game to test your understanding of reactants, products and leftovers. Can you get a perfect score on each level?

Resistance in a Wire

Observe changes to the equation and wire as you play with the resistivity, length, and area sliders.

Rutherford Scattering

How did Rutherford figure out the structure of the atom without being able to see it? Simulate the famous experiment in which he disproved the Plum Pudding model of the atom by observing alpha particles bouncing off atoms and determining that they must have a small core.

States of Matter

Watch different types of molecules form a solid, liquid, or gas. Add or remove heat and watch the phase change. Change the temperature or volume of a container and see a pressure-temperature diagram respond in real time. Relate the interaction potential to the forces between molecules.

States of Matter: Basics

Heat, cool and compress atoms and molecules and watch as they change between solid, liquid and gas phases.

Trig Tour

Take a tour of trigonometry using degrees or radians! Look for patterns in the values and on the graph when you change the value of theta. Compare the graphs of sine, cosine, and tangent.

Under Pressure

Explore pressure under and above water. See how pressure changes as you change fluids, gravity, container shapes, and volume.

Unit Rates

Discover the unit rate while shopping for fruits, vegetables, and candy. Construct a double number line and look for patterns. Challenge yourself on the race track as you compare cars with different rates!

Vector Addition

Explore vectors in 1D or 2D, and discover how vectors add together. Specify vectors in Cartesian or polar coordinates, and see the magnitude, angle, and components of each vector. Experiment with vector equations and compare vector sums and differences.

Vector Addition: Equations

Experiment with vector equations and compare vector sums and differences. Customize the base vectors or explore scalar multiplication by adjusting the coefficients in equation. Specify vectors in Cartesian or polar coordinates, and view the magnitude, angle, and components of each vector.

Wave Interference

Make waves with a dripping faucet, audio speaker, or laser! Add a second source to create an interference pattern. Put up a barrier to explore single-slit diffraction and double-slit interference. Experiment with diffraction through elliptical, rectangular, or irregular apertures.

Wave on a String

Explore the wonderful world of waves! Even observe a string vibrate in slow motion. Wiggle the end of the string and make waves, or adjust the frequency and amplitude of an oscillator.

Waves Intro

Make waves with a dripping faucet, audio speaker, or laser! Adjust frequency and amplitude, and observe the effects. Hear the sound produced by the speaker, and discover what determines the color of light.

pH Scale

Test the pH of things like coffee, spit, and soap to determine whether each is acidic, basic, or neutral. Visualize the relative number of hydroxide ions and hydronium ions in solution. Switch between logarithmic and linear scales. Investigate whether changing the volume or diluting with water affects the pH. Or you can design your own liquid!

pH Scale: Basics

Test the pH of everyday liquids such as coffee, spit, and soap to determine whether each is acidic, basic, or neutral. Investigate how adding more of a liquid or diluting with water affects pH.

Number Line: Distance

Subtraction is more than an operation- it is also the distance between two numbers! Explore the distance between a person and house, a bird and a fish, and the difference in temperature between two locations. Compare absolute distance and directed distance, and strengthen your number line muscles.