An explorable introduction to chemistry
Stuff, from the bottom up
Chemistry for people who know some physics and maths but never really got chemistry. Every chapter also includes something to try with a six-year-old.
Chemistry is usually taught as a pile of rules: octets, electron configurations, "like dissolves like". This course goes the other way. It starts from two facts you already believe: atoms attract a little and repel a lot, and the world jiggles at temperature T. Then it shows where the rules come from. Every simulation is live: drag things, slide things, and predict before you press play.
Physics / ML bridge
Where a chemistry idea lines up with something from physics or machine learning, plus where the analogy breaks.Common trap
A misconception that research shows is common and sticky, and the fix.Tell it to a 6-year-old
Look, wonder, try, and one true sentence to read aloud, plus a note for you on what was simplified.Notes like this one flag every place where a picture or model is simplified, so nothing has to be unlearned later.
Dotted-underlined words have a one-line definition. Hover over them or tap them.
- Before we start
- 0Why physicists never quite get chemistryDirac's equation that explains everything and solves nothing, the three ideas behind the course, and a map of how the chapters connect.
- Part A · What stuff is
- 1Atoms and the sticky forceThe two-atom energy well, why sticking releases heat, and why every liquid and solid exists.
- 2Interlude: made in starsWhere the elements come from: the Big Bang, stars, supernovae and neutron-star collisions.
- 3Electrons as cloudsOrbitals as standing waves, and why shells fill the way they do (mostly).
- 4The periodic table as a mapColumns that share the same outer electrons, and the trends across the table.
- Part B · How stuff sticks
- 5Bonds: one electrical storyCovalent bonds as interference, the sliding scale from sharing to stealing, and why salt exists.
- 6Shapes and the forces between moleculesWhy water is bent, sticky and strange.
- 7Many particles: temperature, chance and the Boltzmann factorTemperature as jiggling, entropy as counting, and free energy as energy versus number of ways.
- 8States and solutionsPhase diagrams, melting and boiling as free-energy crossovers, where the sugar goes, and why oil and water don't mix.
- Part C · How stuff changes
- 9Reactions and countingAtoms rearranged, the energy ledger, and the mole.
- 10Speed and catalystsEnergy barriers, why heat speeds things up, and how catalysts open a lower path.
- 11EquilibriumReactions that keep running both ways at once.
- 12Acids and basesPassing protons around, and the red-cabbage rainbow.
- 13RedoxPassing electrons around: rust, batteries, breathing.
- 14Carbon and lifeChemistry that stays far from equilibrium.