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.

This brief video shows the relationship and movement of particles inside an atom.

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 interactive activity from ChemThink, take a closer look at atomic structure, properties, and behaviors.

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.

A technology demonstration that could transform the way humans explore space is nearing its target launch date of June 24, 2019.

This lesson combines a powerpoint lecture and a reading activity to teach students about the theory and structure of atoms. 

Both of these lessons are classroom activities that require students to build models that display understanding of atoms and molecules. One lesson is structured while the other is guided.

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.