Watch alpha particles escape from a polonium nucleus, causing radioactive alpha decay. See how random decay times relate to the half life.

Explore the origin of energy bands in crystals of atoms. The structure of these bands determines how materials conduct electricity.

Explore the origin of energy bands in crystals of atoms. The structure of these bands determines how materials conduct electricity.

Watch beta decay occur for a collection of nuclei or for an individual nucleus.

Watch beta decay occur for a collection of nuclei or for an individual nucleus.

Students gather evidence about the contents of a sealed container and make predictions about the contents. Provides a good introduction to how scientists have determined the composition of atoms.

This activity also works well to discuss the nature of science in developing hypotheses, various ways of collecting data, and drawing supported conclusions.

CK-12 Physical Science Concepts covers the study of physical science for middle school students. The 5 chapters provide an introduction to physical science, matter, states of matter, chemical interactions and bonds, chemical reactions, motion and forces, and the types and characteristics of energy.

Chemistry: Atoms First is a peer-reviewed, openly licensed introductory textbook produced through a collaborative publishing partnership between OpenStax and the University of Connecticut and UConn Undergraduate Student Government Association.

This title is an adaptation of the OpenStax Chemistry text and covers scope and sequence requirements of the two-semester general chemistry course. Reordered to fit an atoms first approach, this title introduces atomic and molecular structure much earlier than the traditional approach, delaying the introduction of more abstract material so students have time to acclimate to the study of chemistry. Chemistry: Atoms First also provides a basis for understanding the application of quantitative principles to the chemistry that underlies the entire course.

This highly visual model demonstrates the atomic theory of matter which states that a gas is made up of tiny particles of atoms that are in constant motion, smashing into each other. Balls, representing molecules, move within a cage container to simulate this phenomenon. A hair dryer provides the heat to simulate the heating and cooling of gas: the faster the balls are moving, the hotter the gas. Learners observe how the balls move at a slower rate at lower "temperatures."

Create a laser by pumping the chamber with a photon beam. Manage the energy states of the laser's atoms to control its output.

Create a laser by pumping the chamber with a photon beam. Manage the energy states of the laser's atoms to control its output.

How did scientists figure out the structure of atoms without looking at them? Try out different models by shooting light at the atom. Check how the prediction of the model matches the experimental results.

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

Produce light by bombarding atoms with electrons. See how the characteristic spectra of different elements are produced, and configure your own element's energy states to produce light of different colors.

When do photons, electrons, and atoms behave like particles and when do they behave like waves? Watch waves spread out and interfere as they pass through a double slit, then get detected on a screen as tiny dots. Use quantum detectors to explore how measurements change the waves and the patterns they produce on the screen.

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?

Explore what makes a reaction happen by colliding atoms and molecules. Design experiments with different reactions, concentrations, and temperatures. When are reactions reversible? What affects the rate of a reaction?

Explore what makes a reaction happen by colliding atoms and molecules. Design experiments with different reactions, concentrations, and temperatures. When are reactions reversible? What affects the rate of a reaction?

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.

This course discusses the principles and methods of statistical mechanics. Topics covered include classical and quantum statistics, grand ensembles, fluctuations, molecular distribution functions, other concepts in equilibrium statistical mechanics, and topics in thermodynamics and statistical mechanics of irreversible processes.