Lessons

Build a foundation in atomic science one lesson at a time. Each page is a separate lesson, grouped by topic below.

The Atomic Fundamentals series is a four-lesson path—Atoms, The Periodic Table, Isotopes, and Radioactive Decay—from basic structure through how unstable nuclei decay. Nuclear Reactions continues with Nuclear Fission and Nuclear Fusion. Then explore Nuclear Reactors by design type.

Atomic Fundamentals

Start here: atoms, the periodic table, isotopes, and radioactive decay—in order.

Build a mental model of atoms—from nucleus and electrons to elements, isotopes, charge, and how atoms join into molecules.

Learn how the periodic table is built, how to read it, and what an element's position reveals about its atoms and chemistry.

Learn how atoms of the same element can have different numbers of neutrons, and why isotopes matter in nature, medicine, and science.

Learn why unstable nuclei decay, the main types of radiation, half-life, and where radioactivity appears in nature and technology.

How nuclei split and fuse, and how that connects to reactors and stars.

Learn how heavy nuclei split, why neutrons sustain chain reactions, and how fission is controlled in reactors to produce energy.

Learn how light nuclei fuse, why stars shine, what fuels fusion on Earth, and why controlled fusion power is still a major engineering challenge.