📚 Year 7 AQA Chemistry: Formula & Theorem Quick Reference Handbook | Year 7 AQA 化学：公式定理速查手册
Welcome to your Year 7 AQA Chemistry quick-reference handbook. This guide brings together the essential formulas, key theorems and must-know rules about particles, atoms, reactions and acids. Use it to check facts, revise for tests, or build a solid foundation for future chemistry learning. Keep it close, and you will soon master the basics!
欢迎使用这本专为 AQA 七年级化学设计的公式定理速查手册。手册汇集了粒子、原子、化学反应以及酸碱等基础内容中最重要的公式、定理和规则。你可以用它查阅知识点、复习备考，或为今后的化学学习打下扎实基础。随身翻阅，快速掌握核心基础！
1. The Particle Model | 粒子模型
All matter is made of tiny particles that are constantly moving. The particle model explains the properties of solids, liquids and gases simply by how these particles are arranged and how they move.
所有物质都由不断运动的微小粒子组成。粒子模型通过粒子的排列方式和运动状态简单地解释了固体、液体和气体的性质。
In solids, particles are packed closely in a regular pattern. They vibrate in fixed positions but cannot move around. This gives solids a fixed shape and a fixed volume.
在固体中，粒子紧密排列成规则的结构。它们在固定位置上振动，但不能自由移动。因此固体具有固定的形状和固定的体积。
In liquids, particles are still close together but are arranged randomly. They can slide past each other, so liquids can flow and take the shape of their container, but they have a fixed volume.
液体中粒子仍然紧密聚集，但排列不规则。粒子可以相互滑动，因此液体能够流动并呈现容器的形状，但体积保持不变。
In gases, particles are far apart and move rapidly in all directions. Gases have no fixed shape and no fixed volume; they spread out to fill any container.
气体中粒子彼此远离，向各个方向快速运动。气体没有固定的形状和体积，会扩散并充满整个容器。
2. States of Matter and Their Properties | 物质的状态和性质
The properties of a substance depend on the arrangement and energy of its particles. Solids are dense and cannot be compressed because their particles are already touching. Liquids are also dense and very difficult to compress, whereas gases can be compressed easily because there is lots of space between the particles.
物质的性质取决于粒子的排列方式和能量高低。固体通常密度大且难以压缩，因为粒子之间已经紧密接触。液体的密度也较大、很难压缩，而气体由于粒子间空隙很大，因而容易被压缩。
When a substance is heated, its particles gain kinetic energy and move faster. This can cause a change of state if the temperature reaches the melting point or boiling point.
当物质被加热时，粒子获得动能并运动得更快。当温度达到熔点或沸点时，物质就可能发生状态变化。
3. Changing States | 状态变化
Melting is the change from solid to liquid. Freezing is the reverse, from liquid to solid. The melting point of a pure substance is fixed; for water it is 0 °C.
熔化是指固体变为液体的过程，凝固则是液体变为固体的逆过程。纯净物具有固定的熔点，例如水的熔点为 0 °C。
Boiling occurs when a liquid turns into a gas throughout the whole liquid, not just at the surface. Evaporation is a slower process that happens only at the surface. The boiling point of water is 100 °C.
沸腾是指整个液体内部都转变为气体的过程，而蒸发则是仅在液体表面发生的较缓慢的过程。水的沸点为 100 °C。
Sublimation is the change from solid directly to gas, skipping the liquid state. Condensation is the change from gas to liquid.
升华是指固体不经过液态直接变为气体的过程，凝华则是气体直接变为固体。冷凝是气体变为液体的过程。
4. Atoms, Elements and Compounds | 原子、元素与化合物
An atom is the smallest particle of an element that can take part in a chemical reaction. All substances are made of atoms. An element is a pure substance made of only one type of atom. Elements are listed on the Periodic Table.
原子是元素参与化学反应的最小粒子。所有物质都由原子构成。元素是由同种原子组成的纯物质，所有元素都列在元素周期表中。
A compound is a substance made of two or more different types of atom chemically bonded together. Compounds have a fixed composition and different properties from the elements they contain. For example, water (H₂O) contains hydrogen and oxygen atoms.
化合物是由两种或两种以上不同原子通过化学键结合形成的纯物质。化合物具有固定的组成，且性质与组成它的元素完全不同。例如，水(H₂O)含有氢原子和氧原子。
Chemical bonds hold atoms together in compounds. When a compound forms, atoms are rearranged but are not created or destroyed.
化学键使原子在化合物中结合在一起。化合物形成时，原子重新排列，但不会被创造或消灭。
5. The Periodic Table | 元素周期表
The Periodic Table arranges all known elements in order of increasing atomic number. Elements with similar chemical properties are placed in the same vertical column, called a group.
元素周期表按原子序数递增的顺序排列所有已知元素。化学性质相似的元素被放在同一纵列，称为族。
Horizontal rows are called periods. Metals are found on the left and centre of the table; non-metals are on the right. The table below shows the first twenty elements and their symbols.
周期表的横排叫作周期。金属元素位于表的左侧和中部，非金属元素位于右侧。下表列出了前二十号元素及其符号。
| Atomic Number | Element | Symbol |
|---|---|---|
| 1 | Hydrogen | H |
| 2 | Helium | He |
| 3 | Lithium | Li |
| 4 | Beryllium | Be |
| 5 | Boron | B |
| 6 | Carbon | C |
| 7 | Nitrogen | N |
| 8 | Oxygen | O |
| 9 | Fluorine | F |
| 10 | Neon | Ne |
| 11 | Sodium | Na |
| 12 | Magnesium | Mg |
| 13 | Aluminium | Al |
| 14 | Silicon | Si |
| 15 | Phosphorus | P |
| 16 | Sulfur | S |
| 17 | Chlorine | Cl |
| 18 | Argon | Ar |
| 19 | Potassium | K |
| 20 | Calcium | Ca |
6. Chemical Symbols and Formulae | 化学符号与化学式
Each element is represented by a unique chemical symbol, usually one or two letters. The first letter is always capitalised. The formula of a compound tells us which elements are present and the ratio of their atoms.
每种元素都有唯一的化学符号，通常是一个或两个字母，第一个字母始终大写。化合物的化学式则表示所包含的元素种类以及原子的个数比。
Subscript numbers show the number of atoms. For example, H₂O means two hydrogen atoms and one oxygen atom. If there is no subscript, it means one atom. The rule for writing a formula: the metal (or the less electronegative element) is usually written first.
下标数字表示原子个数。例如 H₂O 表示两个氢原子和一个氧原子。没有下标则表示一个原子。书写化学式的规则是：一般将金属（或电负性较小的元素）写在前面。
Key formulae to memorise: HCl (hydrochloric acid), H₂SO₄ (sulfuric acid), NaOH (sodium hydroxide), NaCl (sodium chloride), CO₂ (carbon dioxide), CaCO₃ (calcium carbonate).
需要记住的重要化学式：HCl(盐酸)、H₂SO₄(硫酸)、NaOH(氢氧化钠)、NaCl(氯化钠)、CO₂(二氧化碳)、CaCO₃(碳酸钙)。
7. Conservation of Mass | 质量守恒定律
The law of conservation of mass states that the total mass of the reactants is always equal to the total mass of the products in a chemical reaction. Atoms are neither created nor destroyed; they are simply rearranged to form new substances.
质量守恒定律指出：在化学反应中，反应物的总质量总是等于生成物的总质量。原子既不能被创造也不能被消灭，它们只是重新排列形成新物质。
f water is formed: 2H₂ + O₂ → 2H₂O. The mass before and after the reaction stays the same.
例如，当4 g氢气与32 g氧气完全反应时，恰好生成36 g水：2H₂ + O₂ → 2H₂O。反应前后的总质量保持不变。
In an open system, a gas may escape into the air, causing an apparent mass loss. To observe conservation of mass accurately, reactions must be carried out in a closed system.
在敞口体系中，气体可能逸散到空气中，导致质量似乎减少。为了准确观察质量守恒，反应应在封闭体系中进行。
8. Chemical Reactions: Key Patterns | 化学反应：关键模式
Many reactions can be grouped into patterns. Knowing these general equations helps you predict products.
许多化学反应可以归纳为几种典型模式。掌握这些通用方程式有助于预测反应产物。
Combination: tances combine to form one product. General formula: A + B → AB. Example: 2Mg + O₂ → 2MgO.
化合反应：两种或多种物质结合生成一种产物。通式：A + B → AB。例如：2Mg + O₂ → 2MgO。
Decomposition: bstances. General formula: AB → A + B. Example: CaCO₃ → CaO + CO₂ (thermal decomposition).
分解反应：一种化合物分解为更简单的物质。通式：AB → A + B。例如：CaCO₃ → CaO + CO₂（热分解）。
Metal + oxygen → metal oxide. This is an oxidation reaction. Example: 2Cu + O₂ → 2CuO (copper oxide).
金属 + 氧气 → 金属氧化物。这是氧化反应。例如：2Cu + O₂ → 2CuO（氧化铜）。
Metal + acid → salt + hydrogen. ern only for metals that are more reactive than hydrogen. Example: Mg + 2HCl → MgCl₂ + H₂.
金属 + 酸 → 盐 + 氢气。仅适用于比氢活泼的金属。例如：Mg + 2HCl → MgCl₂ + H₂。
Acid + alkali → salt + water. This is a neutralisation reaction. Example: HCl + NaOH → NaCl + H₂O.
酸 + 碱 → 盐 + 水。这是中和反应。例如：HCl + NaOH → NaCl + H₂O。
Acid + metal carbonate → salt + water + carbon dioxide. Example: 2HCl + CaCO₃ → CaCl₂ + H₂O + CO₂.
酸 + 金属碳酸盐 → 盐 + 水 + 二氧化碳。例如：2HCl + CaCO₃ → CaCl₂ + H₂O + CO₂。
9. Reactivity Series of Metals | 金属活动性顺序
The reactivity series lists metals in order of their tendency to lose electrons and form positive ions. A more reactive metal will displace a less reactive metal from its compound.
金属活动性顺序将金属按照失去电子形成阳离子的难易程度排列。活泼性较强的金属能把较不活泼的金属从其化合物中置换出来。
The series, from most reactive to least reactive, can be remembered with a mnemonic: Please Stop Calling Me A Careless Zebra Instead Try Learning How Copper Saves Gold.
从最活泼到最不活泼的顺序可以用助记口诀来记忆：钾钙钠镁铝，碳锌铁锡铅，氢铜汞银铂金。
| Reactivity | Metal | Symbol |
|---|---|---|
| Most reactive | Potassium | K |
| Sodium | Na | |
| Calcium | Ca | |
| Magnesium | Mg | |
广告 / Sponsored 牛津IGCSE化学国际考试教材课本 AQA International GCSE Chemistry for Oxfo… 化学 备考教辅 · 正版现货 · 与本文内容相关 查看详情 / View on Taobao参考价 ¥385.0
更多咨询请联系16621398022（同微信） 备考资讯每日更新，关注不错过 考纲变化 · 科目分析 · 学习方法  在微信里长按二维码识别关注 或截图后用「扫一扫 → 相册」选择本图 公众号：tutorhao |