📚 Year 7 CIE Chemistry: Vocabulary and Terminology Quick-Reference Guide | Year 7 CIE 化学：词汇术语速记指南
Building a strong chemistry vocabulary is the first step to mastering the subject. In Year 7, you will encounter many new words that describe the building blocks of matter and the ways they behave. This guide introduces key terms with clear definitions and examples, helping you remember them quickly for your CIE course.
构建扎实的化学词汇是掌握这门学科的第一步。在七年级，你会接触到许多描述物质构成及其行为方式的新词。本指南介绍关键术语，配以清晰的定义和示例，帮助你快速记忆，以应对CIE课程。
1. Atoms and Elements | 原子与元素
An atom is the smallest particle of a chemical element that can exist. Everything around you is made of atoms. They are so tiny that you cannot see them even with a regular microscope.
原子是化学元素能够存在的最小粒子。你周围的一切都由原子构成。它们极其微小，即使用普通显微镜也无法看见。
An element is a pure substance made up of only one type of atom. There are about 118 known elements, such as oxygen, carbon, and iron. Each element has a unique symbol, like O for oxygen and Fe for iron.
元素是由仅一种原子组成的纯净物。已知元素大约有118种，例如氧、碳和铁。每种元素都有一个独特的符号，如氧的符号是O，铁的符号是Fe。
Tip: Think of an element as a single ingredient that cannot be broken down into simpler substances by ordinary chemical means.
小提示：把元素想象成单一成分，无法通过普通化学方法进一步分解为更简单的物质。
2. Molecules and Compounds | 分子与化合物
A molecule is formed when two or more atoms join together chemically. The atoms can be of the same element, like O₂ (oxygen gas), or of different elements, like H₂O (water).
分子是两个或更多原子通过化学键结合而形成的。原子可以来自同一种元素，如O₂（氧气），也可以来自不同元素，如H₂O（水）。
A compound is a substance made from two or more different elements that are chemically bonded. Water (H₂O) and carbon dioxide (CO₂) are compounds because they contain more than one type of element.
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。水（H₂O）和二氧化碳（CO₂）都是化合物，因为它们含有不止一种元素。
All compounds are molecules, but not all molecules are compounds. An oxygen molecule (O₂) is a molecule but not a compound because it contains only one type of atom.
所有化合物都是分子，但并非所有分子都是化合物。氧分子（O₂）是分子但不是化合物，因为它只含有一种原子。
3. Mixtures vs Pure Substances | 混合物与纯净物
A pure substance contains only one type of particle – either atoms of a single element or molecules of a single compound. Pure water is a pure substance because it contains only H₂O molecules.
纯净物只含一种粒子，可以是单质元素的原子，也可以是单一化合物的分子。纯水是纯净物，因为它只含有H₂O分子。
A mixture consists of two or more different substances that are not chemically joined. Air is a mixture of gases like nitrogen, oxygen, and carbon dioxide, while a salad is a mixture of solid ingredients.
混合物由两种或多种未发生化学结合的纯物质组成。空气是氮气、氧气和二氧化碳等气体的混合物，而沙拉则是各种固体食材的混合物。
Mixtures can usually be separated by physical methods such as filtration, evaporation, or distillation, whereas compounds can only be broken down by chemical reactions.
混合物通常可以通过过滤、蒸发、蒸馏等物理方法进行分离，而化合物只能通过化学反应来分解。
4. States of Matter | 物质的状态
Matter exists in three main states: solid, liquid, and gas. In a solid, particles are closely packed in a fixed arrangement and can only vibrate in place. This gives solids a definite shape and volume.
物质主要以三种状态存在：固态、液态和气态。在固体中，粒子紧密排列成固定结构，只能原地振动。这使得固体具有固定的形状和体积。
In a liquid, particles are close together but can slide past one another. Liquids have a fixed volume but take the shape of their container. In a gas, particles are far apart and move freely, so gases have no fixed shape or volume and fill any container.
在液体中，粒子紧密相邻但可以相互滑动。液体有固定的体积，但会随容器形状改变。在气体中，粒子相距很远并自由运动，因此气体没有固定的形状和体积，会充满整个容器。
The change from solid to liquid is melting, from liquid to gas is evaporation or boiling, and the reverse processes are freezing and condensation.
固体变为液体叫做熔化，液体变为气体叫做蒸发或沸腾，相反的过程分别是凝固和冷凝。
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 does not produce a new substance. Examples include melting ice, tearing paper, or dissolving sugar in water. These changes are often reversible.
物理变化会改变物质的形式或外观，但不会生成新物质。例如冰融化、撕纸或将糖溶于水。这些变化通常可逆。
A chemical change results in the formation of one or more new substances with different properties. Signs of a chemical change include colour change, bubbling (gas release), heat or light production, and formation of a precipitate.
化学变化会产生一种或多种具有不同性质的新物质。化学变化的迹象包括颜色改变、冒泡（释放气体）、产生热或光，以及生成沉淀。
Burning wood, rusting iron, and cooking an egg are all chemical changes. Once a chemical change has occurred, it is usually difficult or impossible to reverse.
木材燃烧、铁生锈和煮鸡蛋都属于化学变化。化学变化一旦发生，通常很难或不可能逆转。
6. The Periodic Table | 元素周期表
The periodic table is a chart that organises all known elements in order of increasing atomic number. Each element is placed in a specific group and period based on its properties.
元素周期表是一个按原子序数递增顺序排列所有已知元素的图表。每种元素根据其性质被放置在特定的族和周期中。
Elements in the same vertical column (group) have similar chemical properties. For example, Group 1 elements are all reactive metals, while Group 18 elements are noble gases that rarely react.
同一竖列（族）的元素具有相似的化学性质。例如，第1族元素都是活泼金属，而第18族元素是惰性气体，很少发生反应。
Key vocabulary: atomic number (number of protons in an atom), mass number (total protons and neutrons), period (horizontal row), group (vertical column).
关键术语：原子序数（原子中的质子数），质量数（质子与中子的总数），周期（横排），族（纵列）。
7. Acids and Alkalis | 酸与碱
An acid is a substance that releases hydrogen ions (H⁺) when dissolved in water. Acids have a sour taste and can be corrosive. Common examples include hydrochloric acid (HCl), sulfuric acid (H₂SO₄), and citric acid found in lemons.
酸是一种溶于水时会释放氢离子（H⁺）的物质。酸有酸味，并可能具有腐蚀性。常见例子包括盐酸（HCl）、硫酸（H₂SO₄）和柠檬中的柠檬酸。
An alkali is a soluble base that releases hydroxide ions (OH⁻) in water. Alkalis feel soapy and can also be corrosive. Sodium hydroxide (NaOH) and potassium hydroxide (KOH) are typical alkalis.
碱是可溶的碱性物质，在水中会释放氢氧根离子（OH⁻）。碱摸起来有滑腻感，也可能具有腐蚀性。氢氧化钠（NaOH）和氢氧化钾（KOH）是典型的碱。
Remember: not all bases are alkalis – only bases that dissolve in water are called alkalis.
记住：并非所有碱性物质都是碱——只有能溶于水的碱性物质才称为碱。
8. pH Scale | pH 值标度
The pH scale measures how acidic or alkaline a solution is. It ranges from 0 to 14. A pH of 7 is neutral, meaning the solution is neither acidic nor alkaline. Pure water has a pH of 7.
pH值标度用于衡量溶液的酸碱性，范围从0到14。pH值为7表示中性，既不呈酸性也不呈碱性。纯水的pH值为7。
Substances with a pH less than 7 are acidic. The lower the pH, the stronger the acid. For example, lemon juice has a pH around 2. Substances with a pH greater than 7 are alkaline. The higher the pH, the stronger the alkali. Household bleach can have a pH of about 12.
pH小于7的物质为酸性，pH越低，酸性越强。例如，柠檬汁的pH值约为2。pH大于7的物质为碱性，pH越高，碱性越强。家用漂白剂的pH值大约为12。
Indicators are substances that change colour at different pH values. Litmus paper turns red in acid and blue in alkali. Universal indicator shows a range of colours depending on pH.
指示剂是能在不同pH值下改变颜色的物质。石蕊试纸在酸中变红，在碱中变蓝。通用指示剂会根据pH值显示一系列颜色。
9. Solutions and Solubility | 溶液与溶解度
A solution is a homogeneous mixture of two or more substances. The solute is the substance that dissolves, and the solvent is the substance that does the dissolving. In saltwater, salt is the solute and water is the solvent.
溶液是两种或多种物质的均一混合物。溶质是被溶解的物质，溶剂是进行溶解的物质。在盐水中，盐是溶质，水是溶剂。
Solubility is the maximum amount of solute that can dissolve in a given amount of solvent at a specific temperature. If a solution contains the maximum amount of dissolved solute, it is saturated.
溶解度是在特定温度下，一定量的溶剂中能够溶解的溶质的最大质量。如果溶液中含有最大量的已溶解溶质，则称为饱和溶液。
Factors affecting solubility include temperature and, for gases, pressure. Stirring and heating often speed up the dissolving process but do not change the solubility itself.
影响溶解度的因素包括温度，对于气体还有压强。搅拌和加热通常能加快溶解速度，但不会改变溶解度本身。
10. Separation Techniques | 分离技术
Filtration is used to separate an insoluble solid from a liquid. For example, sand can be separated from water using filter paper and a funnel. The solid left on the filter paper is called the residue, while the liquid that passes through is the filtrate.
过滤用于将不溶性固体从液体中分离。例如，用滤纸和漏斗可将沙子从水中分离。留在滤纸上的固体叫残渣，穿过滤纸的液体叫滤液。
Evaporation removes a solvent from a solution by heating, leaving the solute behind. Distillation involves boiling a liquid and then condensing the vapour back into a liquid to collect the pure solvent. Simple distillation separates a solvent from a solute, while fractional distillation separates mixtures of liquids with different boiling points.
蒸发通过加热除去溶液中的溶剂，留下溶质。蒸馏则是将液体煮沸，再将蒸气冷凝回液体，以收集纯溶剂。简单蒸馏可分离溶剂与溶质，分馏则用于分离沸点不同的液体混合物。
Chromatography can separate coloured substances in a mixture, such as the different dyes in ink. A drop of the mixture is placed on chromatography paper, and the components travel at different speeds as a solvent moves up the paper.
色谱法可分离混合物中的有色物质，如墨水中的不同染料。将一滴混合物点在色谱纸上，随着溶剂在纸上展开，各组分以不同速度移动。
11. Key Laboratory Equipment | 关键实验室器材
Familiarity with basic lab equipment is essential. A beaker is a wide, cylindrical container used for stirring, mixing, and heating liquids. A conical flask has a narrow neck and is used to mix liquids by swirling without spilling.
熟悉基本实验器材至关重要。烧杯是一种宽口圆柱形容器，用于搅拌、混合和加热液体。锥形瓶瓶颈较窄，可通过摇晃混合液体而不会溅出。
A measuring cylinder provides accurate volume measurements of liquids. A Bunsen burner produces a single open gas flame for heating. A tripod and gauze mat support containers above the flame. Test tubes hold small amounts of substances for experiments.
量筒用于精确测量液体的体积。本生灯能产生可调节的明火用于加热。三脚架和石棉网在火焰上方支撑容器。试管用于盛放少量实验物质。
A thermometer measures temperature, and a balance measures mass. Tongs and test tube holders are used to handle hot apparatus safely.
温度计测量温度，天平测量质量。坩埚钳和试管夹用于安全地夹持热的仪器。
12. Chemical Reactions | 化学反应
A chemical reaction is a process in which substances, called reactants, are transformed into different substances, called products. Reactants are written on the left of a chemical equation, and products on the right, with an arrow showing the direction of change.
化学反应是反应物转化为不同物质（生成物）的过程。化学方程式中反应物写在左侧，生成物写在右侧，用箭头表示变化方向。
Word equations use the names of substances to describe a reaction, e.g., “hydrogen + oxygen → water”. Symbol equations use chemical symbols and formulas, like 2H₂ + O₂ → 2H₂O.
文字方程式使用物质名称描述反应，例如“氢气 + 氧气 → 水”。符号方程式则使用化学符号和化学式，如2H₂ + O₂ → 2H₂O。
The law of conservation of mass states that matter cannot be created or destroyed in a chemical reaction. Therefore, the total mass of reactants equals the total mass of products. Equations must be balanced to reflect this.
质量守恒定律指出，物质在化学反应中既不能被创造也不能被消灭。因此，反应物的总质量等于生成物的总质量。方程式必须配平以体现这一点。
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