📚 Year 8 CIE Chemistry: Vocabulary and Terminology Quick Memory Guide | Year 8 CIE 化学：词汇术语速记指南
Mastering chemistry starts with understanding its language. This guide breaks down the most important terms you will meet in Year 8 CIE Chemistry, with clear definitions and memory tips for each one. Whether you are revising for a test or building a solid foundation for IGCSE, these explanations will help you speak and think like a chemist.
学好化学，从掌握它的语言开始。本指南为你梳理了 Year 8 CIE 化学中最关键的术语，每个术语都配有清晰的定义和记忆小窍门。无论你是在准备测验，还是为 IGCSE 打基础，这些讲解都能帮助你像化学家一样表达和思考。
1. Atoms, Elements & the Periodic Table | 原子、元素与周期表
An atom is the smallest particle of an element that can take part in a chemical reaction. An element is a pure substance made of only one type of atom, and it cannot be broken down into anything simpler by chemical means. The Periodic Table arranges all known elements in order of increasing atomic number, grouping them by similar properties.
原子是能够参与化学反应的元素最小粒子。元素是只由一种原子组成的纯净物，无法通过化学方法再分解成更简单的物质。周期表按照原子序数递增的顺序排列所有已知元素，并将性质相似的元素归为一族。
- Memory tip: Think of the Periodic Table as a giant library where each book (element) has a unique number and is placed on a shelf according to its family.
- 记忆技巧：把周期表想象成一个巨大的图书馆，每本书（元素）都有唯一的编号，并按家族放在对应的书架上。
- Example: Oxygen (O) is an element; a single oxygen atom is the smallest unit that still behaves as oxygen.
- 示例：氧是一种元素；单个氧原子是仍能体现氧的性质的最小单元。
2. Compounds and Molecules | 化合物与分子
A compound is a pure substance made of two or more different elements chemically joined in a fixed proportion. A molecule is a group of two or more atoms held together by covalent bonds; molecules can be elements (like O₂) or compounds (like H₂O). Every compound is made of molecules or ions, but not every molecule is a compound.
化合物是由两种或多种不同元素按一定比例通过化学键结合而成的纯净物。分子是由共价键连接在一起的两个或多个原子组成的基团；分子可以是单质（如 O₂），也可以是化合物（如 H₂O）。每种化合物都由分子或离子构成，但不是每个分子都是化合物。
- Memory tip: 'Compound' = different elements combined; 'molecule' simply means atoms stuck together.
- 记忆技巧：“化合物”一定是不同元素结合；“分子”仅仅意味着原子粘在一起。
| Substance | Type |
|---|---|
| N₂ | Molecule (element) |
| CO₂ | Molecule (compound) |
| NaCl | Ionic compound (not a molecule) |
3. Mixtures and Separation | 混合物与分离
A mixture contains two or more substances (elements or compounds) that are not chemically joined. The components keep their own properties and can be separated by physical methods such as filtration, distillation, chromatography, or evaporation. Unlike compounds, mixtures do not have a fixed composition.
混合物含有两种或多种未通过化学键结合的物质（单质或化合物）。各组分保持自身的性质，并可通过过滤、蒸馏、色谱或蒸发等物理方法分离。与化合物不同，混合物没有固定的组成。
- Memory tip: A fruit salad is a mixture – you can pick out the grapes; a cake is more like a compound once baked, because you cannot easily get back the original egg and flour.
- 记忆技巧：水果沙拉是混合物——你可以把葡萄挑出来；烤好的蛋糕更像化合物，因为你很难再得到原来的鸡蛋和面粉。
4. States of Matter | 物质的状态
The three common states of matter are solid, liquid, and gas. In a solid, particles vibrate in fixed positions and have a definite shape and volume. In a liquid, particles are close together but can move past one another, so a liquid has a fixed volume but takes the shape of its container. In a gas, particles are far apart and move rapidly in all directions, so a gas has no fixed shape or volume.
物质常见的三种状态是固态、液态和气态。固体中，粒子在固定的位置振动，有确定的形状和体积。液体中，粒子紧密排列但能相互滑动，因此液体有固定的体积，但形状随容器而变。气体中，粒子相距很远并快速向各个方向运动，因此气体没有固定的形状和体积。
- Key terms: melting, freezing, boiling, condensation, sublimation. Remember these are physical changes, not chemical ones.
- 重要术语：熔化、凝固、沸腾、冷凝、升华。记住这些都是物理变化，不是化学变化。
5. Physical and Chemical Changes | 物理变化与化学变化
A physical change alters the form or appearance of a substance but not its chemical identity. Examples include cutting paper, melting ice, and dissolving salt in water. A chemical change (a chemical reaction) produces one or more new substances with different properties from the reactants. Signs of a chemical change include colour change, gas production (bubbles), temperature change, and formation of a precipitate.
物理变化只改变物质的形态或外观，不改变其化学本质。例子包括剪纸、冰融化、盐溶于水。化学变化（化学反应）会产生一种或多种与反应物性质不同的新物质。化学变化的标志有颜色变化、产生气体（气泡）、温度变化、生成沉淀等。
- Memory tip: If you can easily reverse the change (like freezing water back to ice), it is probably physical. If a new smell or colour appears and you cannot simply reverse it, that's a chemical change.
- 记忆技巧：如果一个变化可以轻易逆转（比如把水重新冻成冰），它很可能是物理变化。如果出现了新的气味或颜色，并且无法简单逆转，那就是化学变化。
6. Reactions and Equations | 反应与方程式
A chemical reaction involves the rearrangement of atoms to form new substances. Reactants are the starting substances, and products are what we get at the end. A word equation uses the names of the substances: e.g., methane + oxygen → carbon dioxide + water. A symbol equation uses chemical formulae and must be balanced: CH₄ + 2O₂ → CO₂ + 2H₂O.
化学反应涉及原子重新排列以形成新物质的过程。反应物是起始物质，生成物是最终得到的物质。文字方程式使用物质名称，如：甲烷 + 氧气 → 二氧化碳 + 水。符号方程式使用化学式，并且必须配平：CH₄ + 2O₂ → CO₂ + 2H₂O。
- Key vocabulary: oxidation (adding oxygen), reduction (removing oxygen), decomposition, combustion, exothermic (gives out heat), endothermic (takes in heat).
- 关键术语：氧化（加氧）、还原（去氧）、分解、燃烧、放热、吸热。
7. Acids and Alkalis | 酸与碱
An acid is a substance that produces hydrogen ions (H⁺) when dissolved in water. Common acids include hydrochloric acid (HCl), sulfuric acid (H₂SO₄), and nitric acid (HNO₃). An alkali is a soluble base that produces hydroxide ions (OH⁻) in water, such as sodium hydroxide (NaOH). Acids have a sour taste (never taste in a lab!) and alkalis feel soapy.
酸是溶于水时产生氢离子（H⁺）的物质。常见的酸有盐酸（HCl）、硫酸（H₂SO₄）和硝酸（HNO₃）。碱是能溶于水并产生氢氧根离子（OH⁻）的碱性物质，如氢氧化钠（NaOH）。酸有酸味（实验室内绝不可尝！），碱则有滑腻感。
- Memory tip: Acid → H⁺ (think of 'a' for acid and 'h' for hydrogen). Alkali → OH⁻ (think of 'O' and 'H' forming a base).
- 记忆技巧：酸 → H⁺（联想英语 “acid” 和 “hydrogen”）；碱 → OH⁻（氢氧化物的特征）。
8. The pH Scale | pH标度
The pH scale id), 7 is neutral (pure water), and values above 7 are alkaline (14 = very strong alkali). Indicators, such as litmus, phenolphthalein, and universal indicator, change colour depending on pH.
pH标度用来衡量溶液的酸碱度，范围是 0 到 14：小于 7 为酸性（0 为极强酸），7 为中性（纯水），大于 7 为碱性（14 为极强碱）。指示剂如石蕊、酚酞和通用指示剂会随 pH 变化而变色。
| Indicator | Colour in acid | Colour in alkali |
|---|---|---|
| Litmus | Red | Blue |
| Phenolphthalein | Colourless | Pink |
| Universal indicator | Red/orange/yellow | Blue/violet |
9. Neutralisation | 中和
Neutralisation . For example, hydrochloric acid reacts with sodium hydroxide to form sodium chloride (common salt) and water.
中和是酸与碱（或可溶性碱）反应生成盐和水的反应。中和的离子方程式是：H⁺(aq) + OH⁻(aq) → H₂O(l)。例如，盐酸与氢氧化钠反应生成氯化钠（食盐）和水。
- Memory tip: 'Acid + Base → Salt + Water' pends on the acid (e.g., hydrochloric acid gives chlorides, sulfuric acid gives sulfates).
- 记忆技巧：“酸 + 碱 → 盐 + 水”是 Year 8 化学中最有用的文字方程式之一。盐的种类取决于所用的酸（例如，盐酸生成氯化物，硫酸生成硫酸盐）。
10. Metals and Non‑metals | 金属与非金属
Metals are typically shiny, good conductors of heat and electricity, malleable (can be hammered into shape), and ductile (can be drawn into wires). They tend to lose electrons to form positive ions. Non‑metals are usually dull, poor conductors (insulators), and brittle when solid. They tend to gain electrons to form negative ions or share electrons in covalent bonds.
金属通常有光泽，是热和电的良导体，具有延展性（可锤打成形）和可锻性（可拉成丝）。它们倾向失去电子形成阳离子。非金属一般无光泽，是热和电的不良导体（绝缘体），固态时质脆。它们倾向获得电子形成阴离子，或者在共价键中共享电子。
- Memory aid: The 'metal staircase' on the Periodic Table separates metals (left) from non‑metals (right). Elements along the staircase like silicon are often metalloids.
- 记忆辅助：周期表上的“金属阶梯”将金属（左边）与非金属（右边）分开。阶梯附近的元素如硅通常是准金属。
11. Reactivity Series | 活动性顺序
The reactivity series is a list of metals arranged in order of how vigorously they react. A more reactive metal can displace a less reactive metal from its compound. A common mnemonic is: Please (potassium) Stop (sodium) Calling (calcium) My (magnesium) Aunt (aluminium) Zelda (zinc), I (iron) Love (lead) Her (hydrogen) Cool (copper) Silver (silver) Gold (gold).
活动性顺序是按金属反应活泼程度排列的顺序表。活泼金属能将不活泼金属从其化合物中置换出来。一个常见的中文记忆口诀是：“嫁给那美女，身体细纤轻，总共一百斤”（钾、钙、钠、镁、铝、锌、铁、锡、铅、氢、铜、汞、银、铂、金）。
- Key word: displacement – when a more reactive element takes the place of a less reactive element in a compound.
- 关键词：置换——较活泼的元素将较不活泼的元素从其化合物中替换出来。
12. Key Laboratory Equipment | 主要实验设备
Knowing the names of apparatus prevents accidents and saves time. Essential items include: beaker (for holding or heating liquids), conical flask (for swirling without spillage), measuring cylinder (for measuring liquid volume), Bunsen burner (heat source), test tube (for small reactions), evaporating dish (to evaporate solutions), and filter funnel (for filtration).
熟悉仪器名称能避免事故并节省时间。必备器材包括：烧杯（用于盛放或加热液体）、锥形瓶（可用于振荡而液体不易溅出）、量筒（量取液体体积）、本生灯（热源）、试管（用于少量反应）、蒸发皿（蒸发溶液）以及漏斗（用于过滤）。
- Also remember: tripod, gauze, heat‑proof mat, tongs, and spatula. Always draw apparatus in 2D cross-section with clean, simple outlines.
- 另外请记住：三脚架、石棉网、隔热垫、坩埚钳和药匙。画仪器图时请用清晰、简单的线条画出二维剖面图。
Published by TutorHao | Chemistry Revision Series | aleveler.com
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