📚 SQA Year 8 Chemistry: A Fast-Track Guide to Key Terms and Vocabulary | SQA 八年级化学：关键术语速记指南
Mastering the language of chemistry is the first step to understanding how the world works at the molecular level. This guide presents the essential terms you need to know for Year 8 SQA Chemistry, arranged in clear, memorable sections with English–Chinese pairings to support bilingual learners. Each term is explained with context, and visual symbols and tables help fix the concepts in your memory for quick recall during tests and practical work.
掌握化学语言是理解分子层面世界运作方式的第一步。本指南精心整理了 SQA 八年级化学你必须掌握的核心术语，分节讲解，并提供中英对照，帮助双语学习者加深记忆。每个术语都配有语境说明，利用视觉符号和表格将概念牢牢锁在你的记忆中，便于考试和实验时快速提取。
1. Atoms and Elements | 原子与元素
An atom is the smallest particle of an element that can take part in a chemical reaction. Atoms are made of protons (+), neutrons (0), and electrons (−). An element is a pure substance made of only one type of atom, such as oxygen or iron.
原子是能参与化学反应的元素最小粒子。原子由质子 (+)、中子 (0) 和电子 (−) 构成。元素是仅由一种原子组成的纯净物，例如氧或铁。
The atomic number tells you how many protons are in the nucleus. For example, sodium has atomic number 11, so it has 11 protons and 11 electrons when neutral.
原子序数告诉你原子核中有多少个质子。例如钠的原子序数是 11，所以中性钠原子有 11 个质子和 11 个电子。
- atom 原子 — the basic building block of matter 物质的基本构建单位
- element 元素 — a substance made of one type of atom 只含一种原子的物质
- proton 质子 — positive particle in the nucleus 原子核中的正电粒子
- neutron 中子 — neutral particle in the nucleus 原子核中的中性粒子
- electron 电子 — negative particle orbiting the nucleus 绕原子核运动的负电粒子
- nucleus 原子核 — central part of an atom containing protons and neutrons 包含质子和中子的原子中心部分
2. Compounds and Molecules | 化合物与分子
A compound is a substance formed when two or more different elements are chemically bonded together. For example, water (H₂O) is a compound of hydrogen and oxygen. A molecule is the smallest unit of a compound that still has the properties of that compound. All compounds have molecules, but not all molecules are compounds (e.g., O₂ is a molecule but not a compound).
化合物是由两种或两种以上不同元素通过化学键结合而形成的物质。例如水 (H₂O) 是氢和氧的化合物。分子是保留该化合物性质的最小单元。所有化合物都有分子，但并非所有分子都是化合物（如 O₂ 是分子但不是化合物）。
Chemical formulas show the symbols and ratios of atoms. The subscript number tells how many atoms of that element are present. In CO₂, one carbon atom is bonded to two oxygen atoms.
化学式表示原子的符号和比例。下标数字表示该元素的原子个数。在 CO₂ 中，一个碳原子与两个氧原子结合。
| Term 术语 | Meaning 含义 |
|---|---|
| compound 化合物 | substance made from different elements chemically combined 不同元素化学结合而成的物质 |
| molecule 分子 | two or more atoms held together by covalent bonds 由共价键结合的两个或多个原子 |
| bond 化学键 | the force holding atoms together 原子之间的结合力 |
3. The Periodic Table | 元素周期表
The periodic table is a chart organising all known elements by increasing atomic number. Elements in the same vertical column (group) have similar chemical properties. For instance, Group 1 elements are the alkali metals – they are very reactive and have one electron in their outer shell.
元素周期表是按原子序数递增排列所有已知元素的图表。同一纵列（族）的元素化学性质相似。例如第 1 族元素是碱金属，它们反应性很强，最外层只有一个电子。
Rows are called periods. As you move from left to right across a period, the properties change gradually from metallic to non-metallic. Silicon is a metalloid found in the middle.
横行叫周期。在周期中从左到右，性质从金属性逐渐变为非金属性。硅是位于中间位置的准金属。
- group 族 — a vertical column; elements have the same number of outer electrons 纵列；元素最外层电子数相同
- period 周期 — a horizontal row; number of electron shells increases across periods 横行；周期内电子层数递增
- alkali metal 碱金属 — Group 1 reactive metals (Li, Na, K…) 第 1 族活泼金属（锂、钠、钾等）
- halogen 卤素 — Group 7 reactive non-metals (F, Cl, Br…) 第 7 族活泼非金属（氟、氯、溴等）
- noble gas 稀有气体 — Group 0/8 unreactive gases (He, Ne, Ar…) 第 0/8 族不活泼气体（氦、氖、氩等）
4. Chemical Reactions | 化学反应
A chemical reaction happens when substances rearrange their atoms to form new substances. The starting materials are called reactants, and the new substances produced are called products. During a reaction, atoms are never created or destroyed; they are only rearranged. This is the law of conservation of mass.
当物质中的原子重新排列形成新物质时，就发生了化学反应。起始物质叫反应物，生成的新物质叫生成物。反应过程中，原子既不会凭空产生也不会消失，只是重新组合。这就是质量守恒定律。
Signs of a chemical reaction include colour change, temperature change, gas production (bubbles or fizzing), and formation of a precipitate (a solid that appears from two clear solutions).
化学反应的现象包括颜色变化、温度变化、气体产生（气泡或嘶嘶声）以及沉淀生成（从两种清液中出现的固体）。
2H₂ + O₂ → 2H₂O
Hydrogen + Oxygen → Water | 氢气 + 氧气 → 水
- reactant 反应物 — substance that is used up in a reaction 反应中被消耗的物质
- product 生成物 — substance made in a reaction 反应中产生的物质
- precipitate 沉淀 — an insoluble solid formed in a solution reaction 溶液反应中形成的不溶性固体
- conservation of mass 质量守恒 — total mass of reactants = total mass of products 反应物总质量 = 生成物总质量
5. States of Matter | 物态
Matter exists in three common states: solid, liquid, and gas. The state depends on the arrangement and energy of particles. In a solid, particles are tightly packed in a regular pattern and vibrate in fixed positions. In a liquid, particles are close but can slide past each other. In a gas, particles are far apart and move rapidly in all directions.
物质通常以三种状态存在：固态、液态和气态。状态取决于粒子的排列与能量。固态时，粒子紧密规则排列，只能在固定位置振动；液态时，粒子接近但能彼此滑动；气态时，粒子相距很远，朝各个方向快速运动。
uid → gas, condensation is gas → liquid. Sublimation is solid → gas directly, like dry ice (solid CO₂).
状态变化是物理变化，不是化学变化。熔化是固态→液态（吸热），凝固是液态→固态。蒸发是液态→气态，冷凝是气态→液态。升华是固态直接变气态，如干冰 (固体 CO₂)。
| Change 变化 | From → To 从……到…… | Heat energy 热量 |
|---|---|---|
| melting 熔化 | solid → liquid | taken in 吸收 |
| freezing 凝固 | liquid → solid | given out 放出 |
| evaporation 蒸发 | liquid → gas | taken in 吸收 |
| condensation 冷凝 | gas → liquid | given out 放出 |
6. Acids and Alkalis | 酸与碱
Acids are substances that release hydrogen ions (H⁺) when dissolved in water. They taste sour (though you never taste chemicals in the lab!) and turn blue litmus paper red. Common lab acids include hydrochloric acid (HCl), sulfuric acid (H₂SO₄), and nitric acid (HNO₃).
酸是溶于水时释放出氢离子 (H⁺) 的物质。它们尝起来酸酸的（但实验室绝不可品尝化学品！），能使蓝色石蕊试纸变红。实验室常见酸有盐酸 (HCl)、硫酸 (H₂SO₄) 和硝酸 (HNO₃)。
Alkalis are soluble bases that release hydroxide ions (OH⁻) in water. They feel soapy and turn red litmus paper blue. Examples include sodium hydroxide (NaOH) and potassium hydroxide (KOH). The pH scale (0–14) measures acidity: pH < 7 is acidic, pH 7 is neutral, pH > 7 is alkaline. Neutralisation is the reaction between an acid and a base to form salt and water.
碱是溶于水时释放出氢氧根离子 (OH⁻) 的可溶性基底物。它们触感滑腻，使红色石蕊试纸变蓝。例子有氢氧化钠 (NaOH) 和氢氧化钾 (KOH)。pH 标度（0–14）衡量酸碱度：pH < 7 为酸性，pH 7 为中性，pH > 7 为碱性。中和反应是酸与碱反应生成盐和水。
HCl + NaOH → NaCl + H₂O
acid + alkali → salt + water | 酸 + 碱 → 盐 + 水
7. Mixtures and Separation | 混合物与分离
A mixture contains two or more substances that are not chemically combined. Each substance keeps its own properties. Air is a mixture of gases (mainly nitrogen, oxygen, and argon). Mixtures can be separated using physical techniques because the components have different physical properties.
混合物包含两种或多种未通过化学键结合的物质，各物质保持自身特性。空气是气体混合物（主要含氮气、氧气和氩气）。利用各组分物理性质的差异，可以用物理方法分离混合物。
Key separation methods: filtration (separates insoluble solid from liquid, using filter paper), evaporation (removing solvent to leave dissolved solid behind), distillation (separating liquids with different boiling points), and chromatography (separating coloured substances in a solvent).
关键分离方法：过滤（用滤纸将不溶性固体与液体分离）、蒸发（蒸去溶剂留下溶解的固体）、蒸馏（利用沸点不同分离液体混合物）以及色谱法（在溶剂中分离有色物质）。
| Method 方法 | Separates 分离对象 | Principle 原理 |
|---|---|---|
| filtration 过滤 | solid + liquid 固液 | particle size 颗粒大小 |
| evaporation 蒸发 | soluble solid from solution 溶质与溶剂 | boiling point difference 沸点差 |
| distillation 蒸馏 | two liquids 两种液体 | boiling point difference 沸点差 |
| chromatography 色谱 | coloured mixtures 有色混合物 | solubility in solvent 在溶剂中的溶解度 |
8. Energy in Reactions | 反应中的能量
Chemical reactions involve energy changes. Exothermic reactions release energy to the surroundings, usually making the container feel hot. Combustion (burning) and neutralisation are exothermic. Endothermic reactions absorb energy from the surroundings, causing the temperature to drop. Photosynthesis and dissolving ammonium nitrate in water are endothermic.
化学反应伴随能量变化。放热反应向环境释放能量，容器通常感觉变热。燃烧和中和反应是放热的。吸热反应从环境中吸收能量，导致温度下降。光合作用和硝酸铵溶于水是吸热的。
You can measure these changes with a thermometer. A simple lab example: adding magnesium ribbon to hydrochloric acid — the test tube warms up, proving the reaction is exothermic.
你可以用温度计测量这些变化。一个简单的实验室例子：将镁条加入盐酸中，试管变热，证明反应是放热的。
- exothermic 放热 — energy exits, ΔT rise (e.g., combustion) 能量释放，温度上升（如燃烧）
- endothermic 吸热 — energy enters, ΔT fall (e.g., ice pack reaction) 能量吸收，温度下降（如冰袋反应）
- combustion 燃烧 — rapid reaction with oxygen releasing heat and light 与氧气的快速反应，放出热和光
- activation energy 活化能 — minimum energy needed to start a reaction 启动反应所需的最低能量
9. Key Equations and Symbols | 关键方程式与符号
issolved in water). For example, the reaction of calcium carbonate with hydrochloric acid:
会写、会读化学方程式是核心能力。状态符号很重要：(s) = 固体，(l) = 液体，(g) = 气体，(aq) = 水溶液（溶于水）。例如碳酸钙与盐酸的反应：
CaCO₃(s) + 2HCl(aq) → CaCl₂(aq) + CO₂(g) + H₂O(l)
You must balance chemical equations so the number of atoms of each element is the same on both sides. Start by counting atoms, then add coefficients (big numbers in front), never change subscripts.
你必须配平化学方程式，使两边每种元素的原子数目相等。从计算原子数开始，然后添加化学计量数（前面的数字），切勿改动下标。
Common hazard symbols also appear: flammable, corrosive, toxic, irritant, oxidising, environmental hazard. Recognising these keeps you safe in the lab.
常见危险符号也会出现：易燃、腐蚀性、有毒、刺激性、氧化性、环境危害。认出这些符号能保障你在实验室的安全。
10. Common Laboratory Equipment | 常用实验器材
Knowing the names of apparatus is essential for practical work. A beaker holds liquids, a conical flask allows swirling without splashing, a measuring cylinder measures volumes accurately, a test tube holds small amounts, and a Bunsen burner provides a controllable flame.
认识仪器名称对实验操作至关重要。烧杯用于盛放液体，锥形瓶方便摇动而不溅出，量筒精确测量体积，试管盛放少量物质，本生灯提供可控火焰。
When heating, always point the test tube mouth away from people, use a blue (non‑luminous) flame, and wear safety goggles. The pipette and burette are used for precise volume transfers, often in titrations.
加热时，试管口必须远离旁人，使用蓝色（不发光）火焰，并佩戴护目镜。移液管和滴定管用于精确移取体积，常用于滴定实验。
| Equipment 器材 | Use 用途 |
|---|---|
| beaker 烧杯 | holding, mixing, heating liquids 盛装、混合、加热液体 |
| conical flask 锥形瓶 | mixing by swirling without splashing 旋转混匀不溅出 |
| measuring cylinder 量筒 | measuring precise liquid volumes 测量准确液体体积 |
| Bunsen burner 本生灯 | safe, adjustable flame for heating 安全可调火焰用于加热 |
11. Chemical Names and Everyday Language | 化学名称与日常用语
Many chemicals have common names that differ from their systematic names. For example, table salt is sodium chloride (NaCl), baking soda is sodium hydrogen carbonate (NaHCO₃), and vinegar contains ethanoic acid (CH₃COOH). Learning these links helps you see chemistry in everyday life.
许多化学物质有区别于系统名称的俗名。例如食盐是氯化钠 (NaCl)，小苏打是碳酸氢钠 (NaHCO₃)，醋里含有乙酸 (CH₃COOH)。掌握这些联系能帮你从日常生活中发现化学。
Diatomic elements such as H₂, N₂, O₂, F₂, Cl₂, Br₂, I₂ are always written as two atoms when uncombined. Remember ‘BrINClHOF’ or the phrase ‘I Bring Clay For Our New House’ for mnemonic. This avoids common formula errors.
双原子分子如 H₂、N₂、O₂、F₂、Cl₂、Br₂、I₂ 在非化合状态下总是写成两个原子。记住 “BrINClHOF” 或“I Bring Clay For Our New House” 助记口诀，避免常见化学式错误。
Word equations are used to describe reactions in everyday language: ‘ cid → zinc chloride + hydrogen’. They are the bridge before writing full symbol equations.
文字表达式用日常语言描述反应：“锌 + 盐酸 → 氯化锌 + 氢气”。这是书写完整符号方程式前的过渡。
- common name 俗名 — everyday name for a chemical (e.g., vinegar) 化学品的日常名称（如醋）
- systematic name 系统名 — IUPAC name showing composition (e.g., ethanoic acid) 表示组成的 IUPAC 名称（如乙酸）
- diatomic 双原子分子 — molecule containing two identical atoms (O₂) 含两个相同原子的分子（O₂）
- word equation 文字表达式 — describes a reaction using names, not symbols 用名称而非符号描述反应
12. Summary and Quick Review | 总结与快速回顾
This guide has covered the essential SQA Year 8 Chemistry vocabulary, from the structure of the atom through to laboratory equipment. Keep these key headings in mind: atoms and elements, compounds, the periodic table, chemical reactions, states of matter, acids and alkalis, mixtures and separation, energy changes, equations and symbols, and lab apparatus. Each section builds your fluency in chemistry language.
本指南涵盖了 SQA 八年级化学核心词汇，从原子结构到实验室器材。请牢记这些关键标题：原子与元素、化合物、周期表、化学反应、物态、酸与碱、混合物与分离、能量变化、方程式与符号、实验器材。每个部分都在建立你的化学语言流利度。
For effective revision, make flashcards with the term on one side and the definition (in English or Chinese) on the other. Practise drawing and labelling apparatus, and write a word equation for a common reaction each day. The more you use the language, the more naturally it will come during assessments.
为了高效复习，可以制作抽认卡，正面写术语，背面写定义（英文或中文）。练习绘制并标注实验仪器，每天为一种常见反应写一个文字表达式。你越多使用这种语言，考试时它就会越自然地浮现在脑海。
Published by TutorHao | Chemistry Revision Series | aleveler.com
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