📚 Year 7 WJEC Chemistry: Transition Guide | Year 7 WJEC 化学：升学衔接指南
Welcome to your Year 7 Chemistry Transition Guide! Moving from primary school to secondary science is exciting. You already know a lot about materials, changes of state and simple experiments. In Year 7, you will build on these ideas using the particle model, the periodic table and chemical reactions. This guide will help you make connections and feel confident about the new concepts you will meet.
欢迎阅读七年级化学衔接指南！从小学科学过渡到中学科学令人兴奋。你已经了解许多关于材料、状态变化和简单实验的知识。在七年级，你将通过粒子模型、周期表和化学反应来进一步学习这些概念。本指南将帮助你建立联系，让你对新概念充满信心。
1. Welcome to Chemistry | 欢迎来到化学世界
Chemistry is the study of matter and how it changes. In primary school, you observed that ice melts, sugar dissolves and sparks may appear when a candle burns. Now you will begin to explain these changes using scientific language and models. You will find out that chemistry is not just about colourful liquids – it explains everything around you, from cooking to the air you breathe.
化学是研究物质及其变化的科学。在小学，你观察到冰会融化、糖会溶解、蜡烛燃烧时可能产生火花。现在你将开始用科学的语言和模型来解释这些变化。你会发现化学不仅仅涉及五颜六色的液体——它解释了你周围的一切，从烹饪到你呼吸的空气。
2. Laboratory Safety | 实验室安全
Working safely in the laboratory is the most important skill you will learn. In primary school, you may have used simple equipment such as beakers and thermometers. In Year 7, you will handle Bunsen burners, acids and alkalis. This is exciting, but you must follow strict safety rules every time.
在实验室里安全操作是你要学习的最重要的技能。在小学，你可能用过烧杯和温度计等简单器材。在七年级，你将接触本生灯、酸和碱。这很令人兴奋，但你必须每次都严格遵守安全规则。
Key safety rules include:
- Always wear safety goggles and a lab coat.
- Tie back long hair and tuck in loose clothing.
- Never eat, drink or taste any chemical.
- Listen carefully to your teacher's instructions and read labels before using any substance.
- Know where the safety equipment, such as the fire extinguisher and eye-wash station, is located.
关键安全规则包括：
- 始终佩戴护目镜和实验服。
- 把长发扎在后面，并将宽松衣物塞好。
- 绝对不进食、饮水或品尝任何化学品。
- 认真听取老师的指导，并在使用任何物质前阅读标签。
- 知道灭火器和洗眼站等安全设备的位置。
In primary school, you learned to be careful with hot water and sharp objects. Now you will extend these habits to include chemical hazards. Hazard symbols on bottles tell you if a substance is flammable, corrosive or harmful. Learning to recognise these symbols is part of your safety training.
在小学，你学会了小心热水和锋利物品。现在，你将把这些习惯扩展到化学危险品。瓶子上的危险标志告诉你某种物质是否易燃、腐蚀或有害。学会识别这些标志是你安全培训的一部分。
3. States of Matter | 物质的状态
You already know that water can be a solid (ice), a liquid (water) or a gas (steam). Year 7 science gives these states precise names and properties. Solids have a fixed shape and fixed volume. Liquids have a fixed volume but take the shape of their container. Gases have no fixed shape and no fixed volume – they spread out to fill any space.
你已经知道水可以是固体（冰）、液体（水）或气体（水蒸气）。七年级科学赋予这些状态精确的名称和性质。固体有固定的形状和固定的体积。液体有固定的体积，但形状随容器变化。气体既没有固定的形状，也没有固定的体积——它们会扩散并充满整个空间。
You also learn that changes of state are physical changes: they are reversible and no new substance is made. The processes you will name include melting, freezing, boiling, evaporating and condensing. In primary school, you may have called boiling 'evaporation', but in Year 7 you distinguish between evaporation (at the surface) and boiling (throughout the liquid).
你还将学到状态变化是物理变化：它们可逆，且没有新物质生成。你将命名的过程包括熔化、凝固、沸腾、蒸发和冷凝。在小学你可能把沸腾也称为'蒸发'，但在七年级，你会区分蒸发（液体表面发生）和沸腾（整个液体内部发生）。
4. The Particle Model | 粒子模型
The particle model is a powerful idea that explains why solids, liquids and gases behave differently. You will learn that all substances are made of tiny particles. In a solid, particles are held in fixed positions and can only vibrate. In a liquid, particles are close together but can slide past each other. In a gas, particles move quickly in all directions and are much further apart.
粒子模型是一个强有力的概念，它解释了为什么固体、液体和气体的行为不同。你将学习到所有物质都由微小粒子构成。在固体中，粒子被固定在位置上，只能振动。在液体中，粒子紧靠在一起，但可以相互滑动。在气体中，粒子快速地向各个方向运动，并且相距很远。
This model helps you understand melting and boiling. When you heat a solid, particles gain energy, vibrate faster, and eventually break free from fixed positions to become a liquid. Further heating gives particles enough energy to overcome all attractions and move far apart, forming a gas. You will draw particle diagrams using circles to show arrangement and motion.
这个模型帮助你理解熔化和沸腾。当你加热固体时，粒子获得能量，振动加快，最终挣脱固定位置变成液体。继续加热给予粒子足够能量克服所有吸引力，相互远离，形成气体。你将用圆圈绘制粒子图，表示排列方式和运动状态。
5. Elements, Compounds and Mixtures | 元素、化合物与混合物
Everything around you is made from about 100 different types of atoms. A substance made of only one type of atom is called an element. You will see elements arranged in the periodic table. Each element has a symbol: O stands for oxygen, C for carbon, Fe for iron. You may have come across some of these symbols on food packets or in science books.
你周围的一切都由大约100种不同类型的原子构成。只由一种原子组成的物质叫做元素。你会在周期表中看到元素的排列。每种元素都有一个符号：O代表氧，C代表碳，Fe代表铁。你可能在食品包装或科学书上看到过其中一些符号。
When atoms of different elements join together chemically, they form a compound. For example, water (H₂O) is a compound made from hydrogen and oxygen atoms bonded together. The properties of a compound are different from the elements that make it. A mixture contains two or more substances that are not chemically combined – like sand and salt. Because they are not bonded, the substances in a mixture can be separated by physical methods.
当不同元素的原子通过化学方式结合时，就形成化合物。例如，水（H₂O）是由氢原子和氧原子结合而成的化合物。化合物的性质不同于组成它的元素。混合物含有两种或更多未通过化学方式结合的物质——比如沙子和食盐。由于没有发生键合，混合物中的物质可以用物理方法分离。
6. Separating Mixtures | 混合物的分离
In Year 7, you will explore practical techniques to separate mixtures. These techniques build on simple sieving and filtering that you might have tried in primary school. You will now use filtration to separate an insoluble solid from a liquid, such as sand from water. Evaporation recovers a dissolved solid from a solution – for example, obtaining salt from salt water.
在七年级，你将探索分离混合物的实践技术。这些技术建立在小学可能尝试过的简单过筛和过滤基础之上。现在你将使用过滤法分离不溶性固体和液体，例如从水中分离沙子。蒸发法从溶液中回收溶解的固体——例如从盐水中得到食盐。
You will also learn about distillation, which is used to obtain pure water from a solution. Distillation involves boiling the liquid and then condensing the vapour back into a liquid, leaving dissolved solids behind. Another exciting technique is chromatography, which separates coloured substances, such as the dyes in ink. These methods are all physical processes; no new substances are made.
你还将学习蒸馏，它用于从溶液中获得纯水。蒸馏包括将液体煮沸，然后将蒸气冷凝回液体，溶解的固体被留在后面。另一个令人兴奋的技术是色谱法，它用来分离有色物质，比如墨水中的染料。这些方法都是物理过程；没有新物质生成。
7. Acids and Alkalis | 酸与碱
Acids and alkalis are groups of chemicals with opposite properties. You may have experienced acids in lemon juice, vinegar or fizzy drinks. Alkalis are found in soap, baking powder and cleaning products. In the lab, you will use hazard symbols to identify corrosive acids and alkalis, and you will learn to handle them safely.
酸和碱是两组性质相反的化学物质。你可能在柠檬汁、醋或汽水中体验过酸。碱存在于肥皂、发酵粉和清洁产品中。在实验室，你将使用危险标志来识别腐蚀性酸和碱，并学会安全地处理它们。
Indicators are special dyes that change colour in acids and alkalis. Litmus paper turns red in acid and blue in alkali. A more advanced indicator is universal indicator, which changes through a whole range of colours depending on the strength of the acid or alkali. You will test harmless household solutions and record your observations.
指示剂是能在酸和碱中变色的特殊染料。石蕊试纸在酸中变红，在碱中变蓝。一种更高级的指示剂是通用指示剂，它会随着酸或碱的强弱变化呈现一系列颜色。你将测试无害的家用溶液并记录观察结果。
8. The pH Scale | pH 标度
The pH scale is a number scale from 0 to 14 that tells you how acidic or alkaline a solution is. Acids have a pH less than 7. The lower the pH, the stronger the acid. Alkalis have a pH greater than 7. The higher the pH, the stronger the alkali. A solution with pH 7 is neutral – pure water is neutral.
pH 标度是从0到14的数字标尺，告诉你溶液的酸性或碱性有多强。酸的 pH 小于7。pH 越低，酸性越强。碱的 pH 大于7。pH 越高，碱性越强。pH 为7的溶液是中性的——纯水就是中性的。
You will use universal indicator solution or pH paper to measure the pH of substances such as milk, shampoo and rainwater. This helps you link the classroom to everyday life. Strong acids and strong alkalis are corrosive and can damage skin and materials, so you will always wear safety goggles when testing them.
你将使用通用指示剂溶液或pH试纸来测量牛奶、洗发水和雨水等物质的pH值。这有助于你将课堂与日常生活联系起来。强酸和强碱具有腐蚀性，会损伤皮肤和材料，因此在测试时一定要佩戴护目镜。
9. Chemical Reactions: Signs and Word Equations | 化学反应：迹象与文字方程式
A chemical reaction is different from a physical change. In a reaction, one or more new substances are formed. You can often spot a reaction by looking for signs: a colour change, bubbles of gas, a change in temperature, or a solid (precipitate) suddenly appearing. For example, when vinegar mixes with bicarbonate of soda, you see vigorous fizzing – a gas is made.
化学反应不同于物理变化。在反应中，会生成一种或多种新物质。你通常可以通过一些迹象发现反应：颜色变化、气泡冒出、温度变化或突然出现固体（沉淀）。例如，当醋与小苏打混合时，你会看到剧烈冒泡——生成了气体。
(what you end with) on the right, linked by an arrow. For instance: magnesium + oxygen → magnesium oxide. This is a simple way to record what happens without using chemical formulas.
你将学习用文字方程式来概括反应。文字方程式左边是反应物（起始物质），右边是产物（最终生成的物质），中间用箭头连接。例如：镁 + 氧气 → 氧化镁。这是一种不用化学式记录反应过程的简便方式。
10. Energy Changes in Reactions | 反应中的能量变化
During a chemical reaction, energy can be transferred to or from the surroundings. Reactions that release heat, making the surroundings warmer, are called exothermic. Burning fuels and the reaction of acids with metals are exothermic. In primary school, you may have felt a hand-warmer getting hot – that is an exothermic reaction.
在化学反应过程中，能量可能转移到周围环境或从周围环境吸收。释放热量、使周围变暖的反应称为放热反应。燃烧燃料以及酸与金属的反应都是放热的。在小学，你可能感觉到暖手宝变热——那正是放热反应。
Reactions that take in heat, making the surroundings cooler, are called endothermic. An example is the reaction between citric acid and sodium hydrogencarbonate, which you may test in class. You will use a thermometer to measure temperature changes and link this to the particle model: in endothermic reactions, particles use energy to break bonds.
吸收热量、使周围变冷的反应称为吸热反应。例如柠檬酸和碳酸氢钠之间的反应，你可能会在课堂上进行测试。你将使用温度计测量温度变化，并将其与粒子模型联系起来：在吸热反应中，粒子利用能量来断裂化学键。
11. Chemistry in Our World | 我们身边的化学
Chemistry is not just something you do in a lab. It explains how bread rises, why iron rusts, and how plants make food. Understanding chemistry helps us develop new materials, treat illnesses and protect the environment. As you move through Key Stage 3, you will explore topics such as the Earth's atmosphere, the rock cycle and climate change – all built on the foundations you set in Year 7.
化学不仅仅是在实验室中进行的活动。它解释面包为何膨胀、铁为何生锈、植物如何制造食物。了解化学有助于我们开发新材料、治疗疾病和保护环境。在第三关键阶段的学习中，你将探索地球大气、岩石循环和气候变化等主题——所有这些都建立在七年级打下的基础之上。
Stay curious, ask questions and always connect what you learn to the world around you. Every observation can lead to a new discovery. Your chemistry journey has just begun, and the skills you build now will help you become a confident young scientist.
保持好奇心，多提问，并始终将你所学的知识与周围世界联系起来。每一次观察都可能带来新的发现。你的化学之旅才刚刚开始，你现在培养的技能将帮助成为一位自信的年轻科学家。
Published by TutorHao | Chemistry Revision Series | aleveler.com
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