Using shell model diagram to relate absorption to emission. Derives relationship between emitted photon and energy levels, the Balmer-Rydberg equation. Created by Jay.

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

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

Anatomy and Physiology is a dynamic textbook for the two-semester human anatomy and physiology course for life science and allied health majors. The book is organized by body system and covers standard scope and sequence requirements. Its lucid text, strategically constructed art, career features, and links to external learning tools address the critical teaching and learning challenges in the course. The web-based version of Anatomy and Physiology also features links to surgical videos, histology, and interactive diagrams.

In this video, David explains how an atom can absorb and emit photons with particular values of energy and how to determine the allowed values.

Chemistry is the study of matter, and all matter is made up of atoms. We will learn about elements, atomic number and mass, isotopes, moles (chemistry moles, not the animal), and compounds.

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!

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.

Calculating electron energy for levels n=1 to 3. Drawing a shell model diagram and an energy diagram for hydrogen, and then using the diagrams to calculate the energy required to excite an electron between different energy levels. Created by Jay.

Using classical physics to calculate the energy of electrons in Bohr model. Solving for energy of ground state and more generally for level n. Created by Jay

Using equation for Bohr model radii to draw shell model for n=1 to 3, and calculating the velocity of a ground state electron. Created by Jay

Using classical physics and vectors, plus assumption that angular momentum of electron is quantized, to derive the equation for Bohr model radii. Created by Jay.

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!

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.