Watch alpha particles escape from a polonium nucleus, causing radioactive alpha decay. See how random decay times relate to the half life.
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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!
Explore the interactions between various combinations of two atoms. Turn on the force arrows to see either the total force acting on the atoms or the individual attractive and repulsive forces. Try the "Adjustable Attraction" atom to see how changing the parameters affects the interaction.
Play with objects on a teeter totter to learn about balance. Test what you've learned by trying the Balance Challenge game.
Watch beta decay occur for a collection of nuclei or for an individual nucleus.
Starting from atoms, see how many molecules you can build. Collect your molecules and see them in 3D!
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!
This simulation lets learners explore how heating and cooling adds or removes energy. Use a slider to heat blocks of iron or brick to see the energy flow. Next, build your own system to convert mechanical, light, or chemical energy into electrical or thermal energy. (Learners can choose sunlight, steam, flowing water, or mechanical energy to power their systems.) The simulation allows students to visualize energy transformation and describe how energy flows in various systems. Through examples from everyday life, it also bolsters understanding of conservation of energy. This item is part of a larger collection of simulations developed by the Physics Education Technology project (PhET).
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.
Build a gene network! The lac operon is a set of genes which are responsible for the metabolism of lactose in some bacterial cells. Explore the effects of mutations within the lac operon by adding or removing genes from the DNA.
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!
How do greenhouse gases affect the climate? Explore the atmosphere during the ice age and today. What happens when you add clouds? Change the greenhouse gas concentration and see how the temperature changes. Then compare to the effect of glass panes. Zoom in and see how light interacts with molecules. Do all atmospheric gases contribute to the greenhouse effect?
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.
Insert channels in a membrane and see what happens. See how different types of channels allow particles to move through the membrane.
Do you ever wonder how a greenhouse gas affects the climate, or why the ozone layer is important? Use the sim to explore how light interacts with molecules in our atmosphere.
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.
Start a chain reaction, or introduce non-radioactive isotopes to prevent one. Control energy production in a nuclear reactor! (Previously part of the Nuclear Physics simulation - now there are separate Alpha Decay and Nuclear Fission sims.)
Learn about different types of radiometric dating, such as carbon dating. Understand how decay and half life work to enable radiometric dating to work. Play a game that tests your ability to match the percentage of the dating element that remains to the age of the object.
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.
Heat, cool and compress atoms and molecules and watch as they change between solid, liquid and gas phases.