A concept page says one idea cleanly, once, in a form you can reread in April and still follow.
That is deliberately the second time you meet the idea. In this course it almost always arrives first as something you did — a set of element cards you sorted before anyone told you the rule, five reactions on a bench with the labels removed, a paperclip you were asked to count the atoms in. The doing comes first because an explanation you have already half-built for yourself sticks, and one handed to you cold does not. So these pages open by naming where the idea was met, and then they say it properly.
They also do the part a lab period never has time for: the mechanism. Not just that ionization energy rises across a period, but why it rises and where it does not. Not just that one reactant runs out first, but why comparing masses will point you at the wrong one. That is the Grade 11 move, and this is where it lives.
Class pages link here. These pages do not go stale, so start here when you are studying, when you missed a class, or when a calculation you followed in the room falls apart at your kitchen table.
The nineteen pages, by unit
Unit 1 — Matter, Chemical Trends, and Bonding
- The Periodic Table as an Argument
- Periodic Trends
- Ionic and Covalent Bonding
- Lewis Structures and Models
- Naming and Formulas
Unit 2 — Chemical Reactions
Acids and bases arrive here rather than later because that is where the oxides turn up, and you cannot talk about what an oxide makes without naming the thing it made. You will meet them again in Unit 4 with a burette in your hand.
Unit 3 — Quantities in Chemical Reactions
- The Mole
- Molar Mass and Composition
- Empirical and Molecular Formulas
- Stoichiometry
- Limiting Reagent and Yield
Unit 4 — Solutions and Solubility
Unit 5 — Gases and Atmospheric Chemistry
Two kinds of page, and they fail differently
A concept page explains. An exercise page such as Naming Practice drills. You need both, and the gap between them is diagnostic.
What your stuck point is telling you
If you can follow the concept page and then freeze on the exercise page, the missing piece is practice, not understanding — do ten more and the freeze goes away. If you can grind through the exercise page but could not explain to somebody why the method works, the missing piece is the concept page, and no amount of extra practice will supply it. Those two problems feel identical from the inside and have opposite fixes.
Five pages in the Reference folder are neither: they are lookup sheets you keep open while you work rather than pages you read once. Polyatomic Ions and Solubility Rules are the two you will open most.