📚 Year 7 CCEA Chemistry: Key Terms & Definitions Memorisation Guide | Year 7 CCEA 化学：词汇术语速记指南
Mastering the vocabulary in Year 7 CCEA Chemistry is the first step to understanding how matter behaves and changes. This guide groups key terms into logical topics and provides simple memory hooks, definitions, and examples to help you learn them quickly and retain them for your tests and practical work.
掌握 Year 7 CCEA 化学词汇是理解物质行为与变化的第一步。本指南将关键术语按主题分组，提供简单的记忆技巧、定义和示例，帮助你快速学习并在考试和实验中牢牢记住它们。
1. States of Matter and Changes of State | 物态与状态变化
Solid: A state of matter with a fixed shape and fixed volume. The particles are arranged in a regular pattern, held tightly together, and can only vibrate in place.
固体：具有固定形状和固定体积的物质状态。粒子排列成规则的结构，彼此紧紧挤压，只能在原位振动。
Liquid: A state of matter that has a fixed volume but takes the shape of the bottom of its container. Particles are close together but can slide past each other and move randomly.
液体：具有固定体积但随容器底部形状变化的物质状态。粒子相互靠近，但可以相互滑动并随机运动。
Gas: A state of matter with no fixed shape and no fixed volume; it expands to completely fill any container. Particles are far apart and move quickly in all directions.
气体：没有固定形状和固定体积的物质状态；它会膨胀并完全充满任何容器。粒子相距很远，向所有方向快速运动。
Melting: The change of state from solid to liquid. This happens when a solid is heated and the particles gain enough energy to break free from their fixed positions. The temperature at which it occurs is the melting point.
熔化：从固态变为液态的过程。当固体被加热、粒子获得足够能量脱离固定位置时发生。发生该变化的温度称为熔点。
Freezing: The reverse of melting; a liquid turns into a solid as it cools. The particles lose energy and settle into a regular pattern. The freezing point is the same temperature as the melting point for a pure substance.
凝固：熔化的逆过程；液体冷却时变成固体。粒子失去能量，形成规则排列。对于纯净物，凝固点与熔点温度相同。
Boiling: The rapid change from liquid to gas that happens throughout the whole liquid at a specific temperature – the boiling point. Bubbles of gas form inside the liquid.
沸腾：在特定温度（沸点）下整个液体内部迅速转变为气体的过程。液体内部会产生气泡。
Evaporation: A slower change from liquid to gas that happens only at the surface of a liquid, and can occur at any temperature. It is why puddles dry up on a warm day.
蒸发：仅在液体表面发生的从液态到气态的缓慢变化，可以在任何温度下进行。这就是为什么温暖的日子里水坑会变干。
Condensation: The change of state from gas to liquid. It occurs when gas particles lose energy, often on a cold surface, for example water droplets on a mirror after a hot shower.
冷凝：从气态转变为液态的过程。当气体粒子失去能量时常在冷的表面上发生，例如热水澡后镜面上的水滴。
Sublimation: A rare change where a solid turns directly into a gas without first becoming a liquid. An example is solid carbon dioxide (dry ice) changing straight into carbon dioxide gas.
升华：固体未经液态直接转变为气体的罕见变化。例如固体二氧化碳（干冰）直接变为二氧化碳气体。
Deposition: The opposite of sublimation – a gas turns straight into a solid. This is how frost forms from water vapour on a freezing morning.
凝华：升华的反过程——气体直接变成固体。这就是在严寒的早晨水蒸气形成霜的过程。
2. The Particle Theory of Matter | 物质粒子理论
Particle theory: The scientific idea that all matter is made up of tiny, moving particles. The behaviour of solids, liquids and gases can be explained by how these particles are arranged and how much energy they have.
粒子理论：所有物质都由微小的、不断运动的粒子组成的科学观点。固体、液体和气体的行为都可以用这些粒子的排列方式和能量大小来解释。
Diffusion: The movement of particles from a region of higher concentration to a region of lower concentration until they are evenly spread. Memory tip: imagine a ‘diffuse’ perfume smell spreading across a room.
扩散：粒子从高浓度区域向低浓度区域运动，直至均匀分布的过程。记忆窍门：想象‘弥漫’的香水味在房间里扩散。
Gas pressure: The force exerted by gas particles when they collide with the walls of their container. More frequent or harder collisions mean higher pressure.
气体压强：气体粒子碰撞容器壁时产生的力。碰撞越频繁或越剧烈，压强就越大。
Energy of particles: In solids, particles have the least energy and only vibrate; in liquids, they have more energy and can move around; in gases, they have the most energy and move rapidly. Heating a substance increases the energy of its particles.
粒子的能量：固体中粒子能量最低、只能振动；液体中粒子能量较高、可以移动；气体中粒子能量最高、运动迅速。给物质加热会增大其粒子的能量。
3. Physical and Chemical Changes | 物理变化与化学变化
Physical change: A change where no new substance is made. Examples include changes of state, dissolving, and cutting. The change is usually easy to reverse.
物理变化：没有新物质生成的变化。例子包括状态变化、溶解和切割。这种变化通常很容易逆转。
Chemical change: A change where one or more new substances are formed. It is often difficult or impossible to reverse. Energy changes, like heat or light, usually accompany it.
化学变化：生成一种或多种新物质的变化。通常很难或不可能逆转。往往伴随有能量变化，如放热或发光。
Reversible change: A change that can be undone, such as melting ice back to water. Most physical changes are reversible.
可逆变化：可以复原的变化，例如冰融化回水。大多数物理变化是可逆的。
Irreversible change: A change that cannot easily be undone, such as baking a cake or burning a match. Most chemical changes are irreversible.
不可逆变化：不容易复原的变化，如烘焙蛋糕或点燃火柴。大多数化学变化是不可逆的。
Signs of a chemical reaction: Colour change, temperature change (without heating or cooling), formation of a gas (bubbles or fizzing), appearance of a solid (precipitate) when two solutions are mixed, or a new smell.
化学反应的迹象：颜色改变、温度变化（没有外加加热或冷却）、产生气体（气泡或嘶嘶声）、两种溶液混合时出现固体（沉淀）、或产生新的气味。
4. Elements, Compounds and Mixtures | 元素、化合物和混合物
Element: A pure substance made of only one type of atom. Elements are listed on the Periodic Table. About 118 elements are known today, such as oxygen (O), iron (Fe) and gold (Au).
元素：只由一种原子组成的纯净物。元素列在元素周期表中。目前已知约 118 种元素，如氧（O）、铁（Fe）和金（Au）。
Atom: The smallest particle of an element that can still take part in a chemical reaction. Think of atoms as tiny building blocks.
原子：元素中能参与化学反应的最小粒子。可以把原子想象成极其微小的积木块。
Compound: A pure substance made from two or more different elements chemically joined together. Compounds have a fixed composition and different properties from the elements they are made of. Water (H₂O) and carbon dioxide (CO₂) are compounds.
化合物：由两种或多种不同元素通过化学键结合而成的纯净物。化合物有固定的组成，并且性质与组成它的元素不同。水（H₂O）和二氧化碳（CO₂）都是化合物。
Molecule: A group of two or more atoms held together by chemical bonds. A molecule can be made of the same element (e.g. O₂) or different elements (e.g. H₂O).
分子：由两个或两个以上原子通过化学键结合在一起形成的微粒。分子可以由同种元素组成（如 O₂），也可以由不同元素组成（如 H₂O）。
Mixture: Two or more substances that are not chemically joined together. Each substance keeps its own properties, and mixtures can often be separated by physical methods like filtration. Air and seawater are mixtures.
混合物：两种或多种未经过化学结合的物质。各物质保持自身的性质，混合物通常可以通过过滤等物理方法分离。空气和海水都是混合物。
Pure substance: In chemistry, a single element or a single compound with a fixed melting and boiling point. Be careful: in everyday language ‘pure’ can mean clean, but in science it means made of only one substance.
纯净物：在化学中，指具有固定熔点和沸点的单一元素或单一化合物。注意：日常用语中‘纯’可能指干净，但在科学中它表示只由一种物质组成。
5. Separation Techniques | 分离技术
Filtration: A method used to separate an insoluble solid from a liquid. The mixture is poured through filter paper; the solid (residue) stays behind, and the liquid (filtrate) passes through.
过滤：用于将不溶性固体与液体分离的方法。混合物倒入滤纸，固体（残渣）被截留，液体（滤液）通过。
Evaporation to dryness: Used to obtain a dissolved solid from a solution by heating so that the liquid evaporates and only the solid remains. This works well for substances that do not decompose on heating, like salt from salt water.
蒸干法：通过加热使液体蒸发、只剩下固体的方法，用来从溶液中获取可溶性固体。适用于加热不分解的物质，如从盐水中得到食盐。
Simple distillation: A process used to separate a liquid from a solution or a mixture of liquids with different boiling points. The solution is heated, the liquid with the lower boiling point evaporates, is cooled and condensed back into liquid, and collected separately.
简单蒸馏：用于从溶液中或沸点不同的液体混合物中分离出液体。加热溶液，沸点较低的液体蒸发，经冷却冷凝回液体并单独收集。
Chromatography: A technique used to separate dissolved substances, such as different coloured inks or food dyes. The mixture travels up a stationary phase (like filter paper) and the components move at different speeds, producing a chromatogram.
色谱法：用于分离溶解的物质（如不同颜色的墨水或食用色素）的技术。混合物沿固定相（如滤纸）向上移动，各组分移动速度不同，形成色谱图。
Magnetic separation: A way of separating magnetic materials (like iron) from non‑magnetic ones (like sulfur or sand) using a magnet. The magnetic pieces are attracted to the magnet and can be lifted away.
磁选分离：利用磁铁将磁性材料（如铁）从非磁性材料（如硫或沙子）中分离的方法。磁性颗粒被磁铁吸引，可以被移走。
6. Acids and Alkalis | 酸和碱
Acid: A substance that releases hydrogen ions (H⁺) when dissolved in water. Acids have a sour taste (but never taste them in the lab!), are corrosive, and turn blue litmus paper red. Examples: hydrochloric acid, lemon juice, vinegar.
酸：溶于水时释放出氢离子（H⁺）的物质。酸有酸味（但在实验室中绝对不要品尝！），具有腐蚀性，能使蓝色石蕊试纸变红。例子：盐酸、柠檬汁、醋。
Alkali: A soluble base that releases hydroxide ions (OH⁻) in water. Alkalis feel slippery and turn red litmus paper blue. Laboratory alkalis include sodium hydroxide solution and calcium hydroxide solution.
碱：可溶的碱类物质，在水中释放氢氧根离子（OH⁻）。碱有滑腻感，能使红色石蕊试纸变蓝。实验室中常见的碱有氢氧化钠溶液和氢氧化钙溶液。
Base: A substance that can neutralise an acid. All alkalis are bases, but not all bases are soluble in water. Metal oxides and metal hydroxides are examples of bases.
碱（泛指）：能够中和酸的物质。所有的碱溶液都是碱类，但并非所有碱都溶于水。金属氧化物和金属氢氧化物都是碱的例子。
Neutral: A substance that is neither acidic nor alkaline. Pure water and a well‑mixed salt solution are neutral. On the pH scale, neutral is pH 7.
中性：既非酸性也非碱性的物质。纯水和充分混合的盐溶液是中性的。在 pH 标度上，中性对应 pH 7。
Neutralisation: The reaction between an acid and a base (or alkali) that produces a salt and water. The general pattern is: acid + base → salt + water. This reaction
Published by TutorHao | Year 7 Chemistry Revision Series | aleveler.com
更多咨询请联系16621398022（同微信）
屏轩国际教育cambridge primary/secondary checkpoint, cat4, ukiset,ukcat,igcse,alevel,PAT,STEP,MAT, ibdp,ap,ssat,sat,sat2课程辅导，国外大学本科硕士研究生博士课程论文辅导