Pearson Edexcel International GCSE in Chemistry · 4CH1
Topic 1 · Principles of chemistry
The foundations everything else is built on: particles and states, separating mixtures, atomic structure, the Periodic Table, moles and equations, and the three types of bonding — plus electrolysis.
18 lessons, covering 60 specification statements: 1.1 · 1.2 · 1.3 · 1.4 · 1.8 · 1.9 · 1.10 · 1.11 · 1.12 · 1.13 · 1.14 · 1.15 · 1.16 · 1.17 · 1.18 · 1.19 · 1.20 · 1.21 · 1.22 · 1.23 · 1.24 · 1.5 · 1.6 · 1.7 · 1.25 · 1.26 · 1.27 · 1.28 · 1.29 · 1.30 · 1.31 · 1.32 · 1.33 · 1.36 · 1.34 · 1.35 · 1.37 · 1.38 · 1.39 · 1.40 · 1.41 · 1.42 · 1.43 · 1.44 · 1.45 · 1.46 · 1.47 · 1.48 · 1.51 · 1.49 · 1.50 · 1.52 · 1.53 · 1.54 · 1.55 · 1.56 · 1.57 · 1.58 · 1.59 · 1.60
The lessons
- The Three States of Matter — What the particles are doing in a solid, a liquid and a gas — and what really changes when ice melts. (1.1, 1.2, 1.3)
- Pure Substances, Mixtures and How to Separate Them — Why a pure substance melts at one temperature, and which separation technique to reach for when. (1.4, 1.8, 1.9, 1.10, 1.11, 1.12, 1.13)
- Inside the Atom — Protons, neutrons and electrons — where they are, what they weigh, what they carry, and how isotopes give an element a decimal mass. (1.14, 1.15, 1.16, 1.17)
- Electronic Configurations and the Periodic Table — Why the table has the shape it has: the group number IS the outer-shell electron count, and everything follows from that. (1.18, 1.19, 1.20, 1.21, 1.22, 1.23, 1.24)
- Solubility and Solubility Curves — Why a solution can be full, why hot water holds more, and how one curve tells you exactly how many crystals you will get back. (1.5, 1.6, 1.7)
- Formulae and Balanced Equations — Why the ash weighs more than the metal, what balancing an equation is really doing, and how to add up a formula mass without losing a bracket. (1.25, 1.26)
- The Mole — Chemists have to count atoms and can only weigh them. The mole is the one idea that turns a mass on a balance into a number of particles. (1.27, 1.28)
- Reacting Masses and Percentage Yield — How much product a reaction should give, how much it actually gives, and why the two are never the same. (1.29, 1.30)
- Empirical and Molecular Formulae — Working out a formula you were never told, from nothing but the masses on a balance. (1.31, 1.32, 1.33, 1.36)
- Concentration and Gas Volumes — Counting particles in a solution you can only measure by volume, and in a gas you cannot weigh at all. (1.34, 1.35)
- Ionic Bonding — Why atoms give electrons away or take them, how far you can predict that from the periodic table, and how to draw it. (1.37, 1.38, 1.39, 1.40)
- Ionic Structures and Their Properties — Why salt melts at 800 °C, why it will not conduct until it does, and why both facts come from the same lattice. (1.41, 1.42, 1.43)
- Covalent Bonding — What two atoms do when neither can afford to give an electron away. (1.44, 1.45, 1.46)
- Simple Molecular Substances — Strong bonds inside, feeble forces outside — and why that makes methane a gas. (1.47, 1.48, 1.51)
- Giant Covalent Structures — The same element, the same bonds — and one form cuts glass while another marks paper. (1.49, 1.50)
- Metallic Bonding — A lattice of positive ions in a sea of electrons that belong to no atom in particular. (1.52, 1.53, 1.54)
- Why Substances Conduct — the Four Structures Compared — One test applied to every structure in the topic, and the two words electrolysis is built on. (1.55, 1.56, 1.57)
- Electrolysis — Using a current to pull a compound apart, and writing down what happens at each electrode. (1.58, 1.59, 1.60)