📚 Year 7 AQA Chemistry: Summer Prep and Bridging Course | Year 7 AQA 化学：暑期预习与衔接课程
Transitioning from primary science to secondary chemistry is an exciting step. This bridging course will help you get a head start on the key ideas you'll explore in Year 7 AQA Chemistry. You'll learn about particles, atoms, chemical reactions, and how we separate mixtures — all while picking up the essential skills for practical work in the lab. Let's begin your journey into the wonderful world of chemistry.
从小学科学过渡到中学化学是令人兴奋的一步。这个衔接课程将帮助你抢先了解 Year 7 AQA 化学中的关键概念。你将学习粒子、原子、化学反应以及如何分离混合物，同时掌握实验室实践的基本技能。让我们一起开启奇妙的化学之旅。
1. Welcome to Secondary Chemistry – What to Expect | 欢迎来到中学化学 – 有什么期待
In Year 7 Chemistry, you'll move beyond describing what you see and start explaining why things happen. You will use scientific models, such as the particle model, to explain the behaviour of solids, liquids and gases. You'll also be introduced to atoms, elements and the periodic table for the first time.
在 Year 7 化学中，你将不再仅仅描述观察到的现象，而是开始解释现象背后的原因。你将使用科学模型（例如粒子模型）来解释固体、液体和气体的行为。你还将首次接触原子、元素和元素周期表。
Practical work is central to secondary science. You will learn to use Bunsen burners safely, measure volumes and masses accurately, and record observations clearly. Developing these skills in Year 7 provides a solid foundation for all later science courses.
实验操作是中学科学的核心。你将学会安全使用本生灯、准确测量体积和质量，并清晰地记录观察结果。在 Year 7 培养这些技能，能为以后所有科学课程打下坚实基础。
2. Safety in the Science Lab | 科学实验室安全
Before any experiment, you must understand laboratory safety rules. Always wear safety goggles to protect your eyes from splashes. Tie back long hair and tuck in loose clothing. Never eat or drink in the lab, and always listen carefully to your teacher’s instructions.
在进行任何实验之前，你必须了解实验室安全规则。始终佩戴护目镜，以保护眼睛免受飞溅物伤害。将长发束起，并塞好宽松的衣物。实验室里严禁吃东西或喝水，并且务必仔细听从老师的指导。
Recognise common hazard symbols: 'flammable' for substances that catch fire easily, 'corrosive' for those that attack skin and metals, and 'toxic' for poisons. Understanding these symbols helps you handle chemicals safely.
认识常见的安全标志：'易燃' 表示容易着火的物质，'腐蚀性' 表示会腐蚀皮肤和金属的物质，'有毒' 表示毒物。理解这些标志有助于安全地处理化学品。
When using a Bunsen burner, always light it with the air hole closed to get a yellow safety flame first. Once ready, you can open the air hole to create a roaring blue flame for heating. Remember to turn the gas off completely after use.
使用本生灯时，务必先在空气孔关闭的情况下点燃，获得黄色安全火焰。准备好后，可以打开空气孔，产生用于加热的强烈蓝色火焰。记住使用后要完全关闭燃气。
3. The Particle Model of Matter | 物质的粒子模型
All matter is made of tiny particles that are constantly moving. The particle model is a simple way to explain the properties of solids, liquids and gases. It states that the energy of the particles and the forces between them determine the state of a substance.
所有物质都由不断运动的微小粒子组成。粒子模型是解释固体、液体和气体性质的一种简单方法。它表明，粒子的能量以及它们之间的作用力决定了物质的状态。
In solids, particles are packed closely together in a regular pattern. They vibrate in fixed positions and have strong forces holding them in place. This is why solids have a fixed shape and cannot be poured.
在固体中，粒子紧密排列成规则的结构。它们在固定的位置上振动，并且相互之间有很强的作用力将其约束。这就是固体有固定形状且无法倾倒的原因。
In liquids, particles are still close but can move past each other. The forces between them are weaker than in solids. Liquids take the shape of their container and can flow.
在液体中，粒子仍然紧密但可以相互滑动。它们之间的作用力比固体中弱。液体会随着容器的形状而改变形状，并能流动。
In gases, particles are far apart and move rapidly in all directions. The forces between particles are extremely weak. Gases spread out to fill any container completely and can be compressed easily.
在气体中，粒子相距很远，并朝各个方向快速运动。粒子之间的作用力极弱。气体会扩散并完全充满任何容器，而且容易被压缩。
4. States of Matter and Changes of State | 物质的状态与状态变化
Matter can change state when it is heated or cooled. Melting is the change from solid to liquid; freezing is the reverse. Boiling and evaporation both turn a liquid into a gas, while condensation turns a gas back into a liquid. Sublimation occurs when a solid turns directly into a gas.
物质受热或冷却时可以改变状态。熔化是从固体变为液体；凝固则相反。沸腾和蒸发都是将液体变为气体，而凝结是将气体变回液体。升华是指固体直接变为气体。
During a change of state, the temperature of a pure substance stays constant until the change is complete. Energy goes into overcoming forces between particles rather than raising the temperature. This is why the temperature plateaus on a heating curve.
在状态变化期间，纯物质的温度保持恒定，直到变化完成。能量用于克服粒子之间的作用力，而不是提高温度。这就是为什么在加热曲线上温度会出现平台。
The table below summarises the properties of solids, liquids and gases using the particle model.
下表使用粒子模型总结了固体、液体和气体的性质。
| State | Particle arrangement | Movement | Shape/Volume |
|---|---|---|---|
| Solid | Regular, very close | Vibrate on the spot | Fixed shape, fixed volume |
| Liquid | Random, close | Can slide past each other | Fills container shape, fixed volume |
| Gas | Random, far apart | Move fast in all directions | Fills container shape and volume |
5. Introduction to Atoms and Elements | 原子与元素简介
An element is a substance made of only one type of atom. Atoms are the smallest particle of an element that can exist. There are over 100 known elements, each with its own symbol. For example, oxygen is O, carbon is C, and sodium is Na (from its Latin name natrium).
元素是仅由一种原子组成的物质。原子是元素能够存在的最小粒子。已知有 100 多种元素，每种都有其独特的符号。例如，氧是 O，碳是 C，钠是 Na（源自其拉丁名 natrium）。
Elements can be classified as metals or non-metals based on their properties. Metals are often shiny, good conductors of heat and electricity, malleable (can be hammered into shape) and ductile (can be drawn into wires). Non-metals are generally dull, brittle and poor conductors.
元素可以根据其性质分为金属和非金属。金属通常有光泽，是热和电的良导体，具有延展性（可锤打成形状）和展性（可拉成丝）。非金属通常暗淡、易碎，并且是不良导体。
In Year 7, you will learn the symbols of the first 20 elements on the periodic table. Practice writing them correctly — always use a capital letter for the first letter and a lowercase for the second letter, e.g. Ca for calcium, not CA.
在 Year 7，你将学习元素周期表上前 20 种元素的符号。练习正确书写：第一个字母大写，第二个字母小写，例如 Ca 代表钙，而不是 CA。
6. The Periodic Table – Organising Elements | 元素周期表 – 元素的组织
The periodic table arranges all known elements in order of increasing atomic number. Elements with similar properties are placed in the same vertical column called a group. For example, Group 1 contains the alkali metals, which are soft and react vigorously with water.
元素周期表将所有已知元素按原子序数递增的顺序排列。性质相似的元素被放在同一纵列中，称为族。例如，第 1 族包含碱金属，它们质地柔软，与水反应剧烈。
A horizontal row is called a period. As you move from left to right across a period, the properties of elements change gradually. The table also separates metals (on the left) from non-metals (on the right), with semi-metals or metalloids along the staircase line.
横排称为周期。当你从左到右移动一个周期时，元素的性质逐渐变化。周期表还将金属（左侧）和非金属（右侧）分开，沿阶梯线分布着半金属或准金属。
Many common elements are diatomic, meaning they exist as molecules made of two atoms bonded together. For instance, hydrogen is H₂, oxygen is O₂, and nitrogen is N₂. You will use these formulas when writing simple chemical equations later.
许多常见元素是双原子的，即它们以两个原子结合在一起的分子形式存在。例如，氢气是 H₂，氧气是 O₂，氮气是 N₂。之后在书写简单化学方程式时，你会用到这些化学式。
7. Compounds and Mixtures – What’s the Difference? | 化合物与混合物 – 有何不同？
A compound is a substance made when two or more different elements are chemically joined together. The atoms are held by chemical bonds, and the compound has properties that are often very different from its original elements. For example, sodium chloride (table salt) is made from the metal sodium and the toxic gas chlorine.
化合物是由两种或多种不同元素通过化学键结合而成的物质。原子通过化学键连接，化合物的性质往往与其组成元素截然不同。例如，氯化钠（食盐）是由金属钠和有毒气体氯气化合而成的。
A mixture contains two or more substances that are not chemically joined. Each substance keeps its own properties, and mixtures are usually easier to separate than compounds. Air is a mixture of gases; seawater is a mixture of water, salt and other dissolved substances.
混合物包含两种或多种未通过化学键结合的物质。每种物质保持其自身的性质，并且混合物通常比化合物更容易分离。空气是气体的混合物；海水是水、盐和其他溶解物质的混合物。
A compound always has a fixed proportion of elements by mass — water is always H₂O. A mixture can have any proportion. This is a key difference you will investigate practically.
化合物总是具有固定的元素质量比例——水总是 H₂O。混合物则可以有任何比例。这是你将在实验中探究的一个关键区别。
8. Chemical Reactions – Signs and Simple Equations | 化学反应 – 迹象与简单方程式
A chemical reaction happens when one or more substances change to make new substances. Signs of a reaction include colour change, a gas being produced (bubbles or fizzing), a solid forming (precipitate), a temperature change or a smell being given off.
当一种或多种物质发生变化形成新物质时，就发生了化学反应。反应的迹象包括颜色变化、产生气体（气泡或嘶嘶声）、生成固体（沉淀）、温度变化或释放出气味。
Chemical reactions can be shown using word equations:
Reactant A + Reactant B → Product C + Product D
化学反应可以用文字方程式表示：
反应物 A + 反应物 B → 生成物 C + 生成物 D
For example, when magnesium burns in oxygen, it forms magnesium oxide. The word equation is:
Magnesium + Oxygen → Magnesium oxide
例如，镁在氧气中燃烧生成氧化镁。文字方程式为：
镁 + 氧气 → 氧化镁
During a reaction, atoms are rearranged but not created or destroyed. This is the law of conservation of mass. You will gradually learn to write symbol equations that show the number of each type of atom is the same on both sides.
在反应过程中，原子重新排列，但不会凭空产生或消失。这就是质量守恒定律。你将逐渐学习书写符号方程式，表明方程式两边每种原子的数目相等。
9. Acids and Alkalis – The Basics | 酸与碱 – 基础知识
Acids and alkalis are chemical opposites. Acids have a sharp, sour taste (though you should never taste chemicals in the lab) and can be corrosive. Common laboratory acids include hydrochloric acid, sulfuric acid and nitric acid.
酸和碱在化学上是相对的。酸有尖锐的酸味（不过你绝不能在实验室品尝化学品），并可能具有腐蚀性。常见的实验室酸包括盐酸、硫酸和硝酸。
Alkalis are soluble bases that feel soapy to the touch and can also be corrosive. Household alkalis include baking soda and cleaning products. A base is any substance that neutralises an acid to form a salt and water.
碱是可溶性碱类，触感滑腻，也可能有腐蚀性。家庭中的碱包括小苏打和清洁产品。碱是任何能中和酸生成盐和水的物质。
The pH scale measures how acidic or alkaline a substance is. It runs from 0 to 14:
- pH 0-6: acidic (the lower the number, the stronger the acid)
- pH 7: neutral (pure water)
- pH 8-14: alkaline (the higher the number, the stronger the alkali)
pH 标度用于衡量物质的酸碱度。范围从 0 到 14：
- pH 0-6：酸性（数字越小，酸性越强）
- pH 7：中性（纯水）
- pH 8-14：碱性（数字越大，碱性越强）
You can test pH using universal indicator, which changes through a whole spectrum of colours. Litmus paper turns red in acid and blue in alkali.
你可以使用通用指示剂来测试 pH，它会呈现出一系列颜色变化。石蕊试纸在酸性溶液中变红，在碱性溶液中变蓝。
10. Separating Mixtures – Practical Techniques | 分离混合物 – 实用技术
Chemists use several techniques to separate mixtures into their pure components. Each technique exploits differences in physical properties, such as boiling point, particle size or solubility.
化学家使用几种技术将混合物分离成纯组分。每种技术都利用物理性质的差异，例如沸点、颗粒大小或溶解度。
Filtration is used to separate an insoluble solid from a liquid. The mixture is poured through filter paper; the solid residue remains on the paper while the liquid filtrate passes through.
过滤用于将不溶性固体从液体中分离出来。混合物通过滤纸倾倒；固体残渣留在纸上，而液体滤液通过滤纸。
Evaporation and crystallisation are used to obtain a soluble solid from a solution. In evaporation, the solvent is boiled off, leaving the solid behind. Crystallisation involves gentle heating to concentrate the solution, then cooling so that crystals form.
蒸发和结晶用于从溶液中获得可溶性固体。蒸发是通过将溶剂蒸干，留下固体。结晶则需要温和加热浓缩溶液，然后冷却，使晶体形成。
Distillation separates a liquid from a mixture by boiling and condensing. Simple distillation collects the pure solvent, while fractional distillation can separate two or more liquids with different boiling points.
蒸馏通过煮沸和冷凝将液体从混合物中分离出来。简单蒸馏收集纯溶剂，而分馏可以分离两种或多种沸点不同的液体。
Chromatography separates mixtures of coloured substances, such as inks or food colourings. The mixture is carried up paper by a solvent; different components travel at different speeds, producing a pattern called a chromatogram.
色谱法用于分离有色物质的混合物，例如墨水或食用色素。混合物被溶剂在纸上推动上行；不同组分以不同速度移动，产生称为色谱图的图案。
11. Energy in Chemical Reactions | 化学反应中的能量
Chemical reactions often involve energy changes. An exothermic reaction releases thermal energy to the surroundings, causing the temperature to rise. Combustion (burning) and neutralisation are common exothermic reactions.
化学反应通常伴随能量变化。放热反应向周围环境释放热能，导致温度升高。燃烧和中和是常见的放热反应。
An endothermic reaction takes in energy from the surroundings, causing a temperature drop. An example is the reaction between citric acid and sodium hydrogen carbonate. Some endothermic processes, like melting, are physical changes rather than chemical reactions.
吸热反应从周围环境吸收能量，导致温度下降。一个例子是柠檬酸与碳酸氢钠的反应。有些吸热过程，如熔化，属于物理变化而非化学反应。
You can monitor energy changes by measuring the temperature before and after a reaction using a thermometer. In Year 7, you will investigate simple energy changes and link them to bonds breaking (energy in) and bonds forming (energy out).
你可以通过用温度计测量反应前后的温度来监测能量变化。在 Year 7，你将探究简单的能量变化，并将其与化学键断裂（吸收能量）和化学键形成（释放能量）联系起来。
12. Key Skills – Observation, Measuring and Recording | 关键技能 – 观察、测量与记录
Being a good scientist means developing strong practical skills. Always make careful observations and write them down immediately. Use correct scientific vocabulary: saying 'a white precipitate formed' is much more precise than 'it went cloudy'.
成为一名优秀的科学家意味着要发展强大的实践技能。始终进行仔细观察，并立即记录下来。使用正确的科学词汇：说 '生成白色沉淀' 远比说 '变浑浊了' 精确得多。
When measuring, read scales at eye level to avoid parallax error. Use a measuring cylinder for approximate volumes, but a pipette or burette for more precise work. Measuring mass uses a balance, and you should always reset it to zero before placing anything on the pan.
测量时，视线与刻度持平以避免视差错误。使用量筒获取大致体积，但若需更高精度则用移液管或滴定管。测量质量使用天平，在放置任何物品前务必将其归零。
Record data in clear tables with headings that include the quantity and unit, e.g. Temperature / °C. You will later plot graphs and draw conclusions. Adopting these good habits now will help you excel throughout your chemistry course.
记录数据时使用清晰的表格，表头要标明数量和单位，例如 温度 / °C。之后你将绘制图表并得出结论。现在就养成这些好习惯，将有助于你在整个化学课程中取得优异成绩。
Published by TutorHao | Chemistry Revision Series | aleveler.com
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