Before class课前预习与准备
A guided first step for each chapter. Choose the topic assigned by your teacher; use the short recall cards before class.每章一份核心知识点预习。按老师指定的任务完成，不必统一按章节赶进度；周末网页预习，周内提示卡回忆。
18 core preparation tasks18 份核心预习任务
All 54 recall cards · PDF ↓54 张提示卡合订本States of Matter
Particles explain the states粒子与物质状态
See how the same particles behave in a solid, a liquid and a gas.
10–15 min · Start preparation ↗02Separating Substances
Choose a separation method选择分离方法
Learn why filtration and evaporation solve different problems.
10–15 min · Start preparation ↗03Atoms and Elements
Meet the atom原子结构与原子中的数字
Meet the atom, read its numbers, and bring one thought to class.
10–15 min · Start preparation ↗04Atoms Combining
From atoms to ions原子如何变成离子
Follow electron transfer and see why opposite ions attract.
10–15 min · Start preparation ↗05Reacting Masses and Chemical Equations
Balance the atoms用原子数配平方程式
Use particle counts to see what a balanced equation means.
10–15 min · Start preparation ↗06Using Moles
The mole as a counting unit用摩尔计量粒子
Connect a familiar mass measurement to a very large particle count.
10–15 min · Start preparation ↗07Redox Reactions
Track oxygen and electrons追踪氧与电子的转移
Recognise oxidation and reduction without memorising a reaction list.
10–15 min · Start preparation ↗08Electricity and Chemical Change
Who carries the charge?谁在传递电荷？
Distinguish electron flow in wires from ion movement in an electrolyte.
10–15 min · Start preparation ↗09Energy Changes and Reversible Reactions
Where does the energy go?能量流向哪里？
Use temperature observations to distinguish exothermic and endothermic changes.
10–15 min · Start preparation ↗10Rates of Reaction
Make collisions count哪些碰撞能发生反应？
Connect reaction rate to collision frequency and collision energy.
10–15 min · Start preparation ↗11Acids, Bases and Salts
Acids, alkalis and neutralisation酸、碱与中和
Use ions and pH to explain what happens when an acid meets an alkali.
10–15 min · Start preparation ↗12The Periodic Table
Read an element’s position从电子排布读元素的位置
Use electron shells to connect group, period and chemical behaviour.
10–15 min · Start preparation ↗13The Behaviour of Metals
Compare metal reactivity比较金属的反应活泼性
Use observations to decide which metal is more reactive.
10–15 min · Start preparation ↗14Making Use of Metals
Choose an extraction route选择金属提取方法
Connect a metal’s reactivity to the method used to obtain it from its ore.
10–15 min · Start preparation ↗15Air and Water
Clean water, pure water饮用水与纯水
See why removing dirt is different from removing dissolved substances.
10–15 min · Start preparation ↗16Some Non-metals and Their Compounds
Recognise hydrogen and ammonia识别氢气与氨气
Read gas-test observations and connect them to the properties of two gases.
10–15 min · Start preparation ↗17Organic Chemistry
Single or double?单键还是双键？
Meet simple hydrocarbons and distinguish an alkane from an alkene.
10–15 min · Start preparation ↗18Polymers
From small molecules to a chain从小分子到长链
Follow an alkene monomer as it becomes part of an addition polymer.
10–15 min · Start preparation ↗Each task introduces selected core ideas; it does not replace the whole chapter. Written explanations are for classroom discussion. Progress saves on the current device.每份预习只覆盖选定的基础知识；英文解释供课堂讨论。当前进度保存在本机。