📚 A-Level Chemistry Essential Vocabulary List | A-Level 化学基础词汇表
Mastering key terminology is crucial for excelling in A-Level Chemistry. This vocabulary list covers fundamental terms across physical, inorganic, and organic chemistry, providing clear definitions and Chinese translations to support bilingual learners. Each term is carefully selected based on common examination specifications, making it a valuable resource for revision and classroom reference.
掌握关键术语对于在A-Level化学中取得优异成绩至关重要。本词汇表涵盖了物理化学、无机化学和有机化学的基础术语，提供清晰的定义和中文翻译，以帮助双语学习者。每个术语都根据常见的考试大纲精心挑选，是复习和课堂参考的宝贵资源。
1. Atomic Structure | 原子结构
Atom: The smallest particle of an element that retains its chemical properties. It consists of a nucleus containing protons and neutrons, with electrons moving around the nucleus in energy levels.
原子：元素的最小粒子，保留其化学性质。它由一个包含质子和中子的原子核以及在能级中绕核运动的电子组成。
Proton: A positively charged subatomic particle found in the nucleus. Its number defines the atomic number (Z) and the identity of the element.
质子：原子核中带正电的亚原子粒子。它的数量定义了原子序数 (Z) 和元素的种类。
Neutron: An uncharged subatomic particle in the nucleus. The mass number (A) is the total number of protons and neutrons.
中子：原子核中不带电的亚原子粒子。质量数 (A) 是质子数和中子数的总和。
Isotope: Atoms of the same element with the same number of protons but different numbers of neutrons. Isotopes have identical chemical properties but slightly different physical properties.
同位素：质子数相同但中子数不同的同一种元素的原子。同位素具有相同的化学性质，但物理性质略有不同。
Ionisation energy: The energy required to remove one mole of electrons from one mole of gaseous atoms to form one mole of gaseous 1+ ions. First ionisation energy is a key concept in periodicity.
电离能：从一摩尔气态原子中移除一摩尔电子以形成一摩尔气态1+离子所需的能量。第一电离能是周期性的一个关键概念。
2. Amount of Substance | 物质的量
Mole: The SI unit for amount of substance. One mole contains exactly 6.02214076 × 10²³ elementary entities (Avogadro constant). It allows chemists to count particles by weighing.
摩尔：物质的量的国际单位。一摩尔恰好包含 6.02214076 × 10²³ 个基本单元（阿伏伽德罗常数）。它使化学家能够通过称重来计数粒子。
Molar mass (Mᵣ): The mass of one mole of a substance, expressed in g mol⁻¹. For elements, it is the relative atomic mass in grams; for compounds, the sum of relative atomic masses.
摩尔质量 (Mᵣ)：一摩尔物质的质量，以 g mol⁻¹ 表示。对于元素，它是以克为单位的相对原子质量；对于化合物，是相对原子质量的总和。
Empirical formula: The simplest whole-number ratio of atoms of each element present in a compound. It is determined from experimental mass or percentage composition data.
实验式：化合物中每种元素原子的最简整数比。它根据实验的质量或百分比组成数据确定。
Concentration: The amount of solute dissolved in a given volume of solvent. Common units are mol dm⁻³ (molarity). In volumetric analysis, concentration is used to calculate unknown amounts via titrations.
浓度：溶解在给定体积溶剂中的溶质的量。常用单位是 mol dm⁻³（摩尔浓度）。在容量分析中，浓度用于通过滴定计算未知量。
Standard solution: A solution whose concentration is accurately known. It is prepared by dissolving a known mass of solute in a volumetric flask and making up to a calibrated volume.
标准溶液：浓度精确已知的溶液。通过将已知质量的溶质溶解在容量瓶中并定容至校准体积来制备。
3. Bonding and Structure | 键合与结构
Ionic bond: The electrostatic attraction between oppositely charged ions formed by the transfer of electrons from a metal to a non-metal. Ionic compounds have high melting points and conduct electricity when molten or aqueous.
离子键：由金属向非金属转移电子形成的带相反电荷离子之间的静电吸引力。离子化合物具有高熔点，并在熔融或水溶液中导电。
Covalent bond: The strong electrostatic attraction between a shared pair of electrons and the nuclei of the bonded atoms. It can be non-polar or polar depending on electronegativity difference.
共价键：共享电子对与成键原子核之间的强静电吸引。根据电负性差异，它可以是非极性或极性的。
Electronegativity: The ability of an atom to attract the bonding pair of electrons in a covalent bond toward itself. Fluorine is the most electronegative element, and this concept explains bond polarity.
电负性：原子在共价键中吸引成键电子对朝向自身的能力。氟是电负性最强的元素，这一概念解释了键的极性。
Hydrogen bond: A strong type of intermolecular force that occurs when hydrogen is bonded to a very electronegative atom (N, O, or F) and attracted to a lone pair on another electronegative atom. It explains the anomalously high boiling points of H₂O and HF.
氢键：一种强类型的分子间作用力，当氢与电负性很强的原子（N、O 或 F）键合并被另一个电负性原子上的孤对电子吸引时发生。它解释了 H₂O 和 HF 异常高的沸点。
Giant covalent structure: A network of atoms held together by strong covalent bonds in a continuous lattice, e.g., diamond, graphite, and silicon dioxide. These substances have very high melting points and may have unique properties like graphite’s conductivity.
巨型共价结构：由强共价键在连续晶格中连接在一起的原子网络，例如金刚石、石墨和二氧化硅。这些物质具有很高的熔点，并可能具有独特的性质，如石墨的导电性。
4. Energetics | 能量学
Enthalpy change (ΔH): The heat energy change measured under constant pressure. It is negative for exothermic reactions (heat released) and positive for endothermic reactions (heat absorbed).
焓变 (ΔH)：在恒压下测量的热能量变化。对于放热反应（释放热量）为负值，对于吸热反应（吸收热量）为正值。
Activation energy (Eₐ): The minimum energy that colliding particles must possess for a reaction to occur. It is represented by the peak of the energy profile diagram and is lowered by catalysts.
活化能 (Eₐ)：碰撞粒子必须具有的最低能量，反应才能发生。它由能量分布图的峰值表示，并会被催化剂降低。
Standard enthalpy of combustion (ΔH°c): The enthalpy change when one mole of a substance is completely burned in oxygen under standard conditions (298 K, 100 kPa). All combustion reactions are exothermic.
标准燃烧焓 (ΔH°c)：在标准条件下（298 K，100 kPa），一摩尔物质在氧气中完全燃烧时的焓变。所有燃烧反应都是放热的。
Hess’s law: The total enthalpy change for a reaction is independent of the route taken, provided the initial and final conditions are the same. It allows calculation of enthalpy changes that are hard to measure directly.
赫斯定律：反应的总焓变与所采取的途径无关，只要初始和最终条件相同。它允许计算难以直接测量的焓变。
Bond enthalpy: The energy required to break one mole of a particular covalent bond in the gaseous state, averaged over a range of compounds. It can be used to estimate reaction enthalpy changes.
键焓：在气态下，断裂一摩尔特定共价键所需的能量，取一系列化合物的平均值。它可用于估算反应焓变。
5. Kinetics | 动力学
Rate of reaction: The change in concentration of a reactant or product per unit time. It is often expressed as mol dm⁻³ s⁻¹ and can be measured by monitoring colour change, gas volume, or mass loss.
反应速率：单位时间内反应物或产物浓度的变化。通常表示为 mol dm⁻³ s⁻¹，可通过监测颜色变化、气体体积或质量损失来测量。
Collision theory: For a reaction to occur, particles must collide with sufficient kinetic energy (≥ activation energy) and with the correct orientation. Raising temperature increases the frequency and energy of collisions.
碰撞理论：要发生反应，粒子必须碰撞且具有足够的动能（≥ 活化能）以及正确的取向。升高温度会增加碰撞的频率和能量。
Catalyst: A substance that increases the rate of a reaction without being chemically consumed itself. It provides an alternative reaction pathway with a lower activation energy. Enzymes are biological catalysts.
催化剂：增加反应速率而自身在化学上不被消耗的物质。它提供一个活化能较低的反应替代路径。酶是生物催化剂。
Rate equation: An experimentally determined expression showing how the rate depends on reactant concentrations. For the reaction A + B → products, the rate equation may be:
速率方程：由实验确定的表达式，表明速率如何取决于反应物浓度。对于反应 A + B → 产物，速率方程可能是：
Rate = k[A]ᵐ[B]ⁿ
Order of reaction: The power to which the concentration of a reactant is raised in the rate equation. Overall order is the sum of m + n. It can be zero, first, second, etc., and is determined empirically.
反应级数：速率方程中反应物浓度升高的幂次。总反应级数是 m + n 的总和。可以是零级、一级、二级等，由实验确定。
6. Chemical Equilibria | 化学平衡
Dynamic equilibrium: The state in a reversible reaction where the forward and reverse reactions proceed at equal rates, so the concentrations of reactants and products remain constant. It requires a closed system.
动态平衡：可逆反应中正反应和逆反应以相等速率进行的状态，因此反应物和产物的浓度保持恒定。它需要一个封闭系统。
Le Chatelier’s principle: If a system at equilibrium is subjected to a change in concentration, pressure, or temperature, the position of equilibrium shifts to counteract that change. This principle is used to predict the best conditions for yield.
勒夏特列原理：如果处于平衡状态的系统受到浓度、压力或温度变化的影响，平衡位置会移动以抵消这种变化。该原理用于预测最佳产率条件。
Equilibrium constant (K꜀): For the homogeneous equilibrium aA + bB ⇌ cC + dD,
平衡常数 (K꜀)：对于均相平衡 aA + bB ⇌ cC + dD，
K꜀ = [C]ᶜ[D]ᵈ / [A]ᵃ[B]ᵇ
The value of K꜀ is constant at a given temperature. A large K꜀ indicates the equilibrium lies to the right (products favoured).
在给定温度下，K꜀ 的值是恒定的。大的 K꜀ 表明平衡偏向右侧（倾向于产物）。
Partial pressure and Kₚ: For gaseous equilibria, Kₚ uses partial pressures instead of concentrations. The partial pressure of a gas is the mole fraction multiplied by total pressure. Kₚ applies only to homogeneous gas-phase reactions.
分压与 Kₚ：对于气体平衡，Kₚ 使用分压而非浓度。气体的分压是摩尔分数乘以总压。Kₚ 仅适用于均相气相反应。
7. Redox | 氧化还原
Oxidation: The loss of electrons from a species. In terms of oxidation state, it is an increase in oxidation number. Oxidation and reduction always occur simultaneously in a redox reaction.
氧化：物种失去电子。就氧化态而言，是氧化数的增加。氧化和还原总是同时发生于氧化还原反应中。
Reduction: The gain of electrons by a species, accompanied by a decrease in oxidation number. A reducing agent is itself oxidised and causes another substance to be reduced.
还原：物种获得电子，同时氧化数降低。还原剂自身被氧化，并使另一物质被还原。
Oxidation state (number): The hypothetical charge an atom would have if all bonds were completely ionic. Rules include: elements have an oxidation state of 0; oxygen is usually -2; hydrogen is +1 with non-metals. The sum of oxidation states in a neutral compound is zero.
氧化态（氧化数）：假设所有键都是完全离子性时，一个原子将具有的假想电荷。规则包括：单质的氧化态为 0；氧通常为 -2；氢与非金属结合时为 +1。中性化合物中氧化态的总和为零。
Half-equation: An equation that shows the electron transfer for either the oxidation or reduction process. For example, the reduction of manganate(VII) ions in acidic medium:
半反应方程式：显示氧化或还原过程的电子转移的方程式。例如，酸性介质中高锰酸根(VII)离子的还原：
MnO₄⁻ + 8H⁺ + 5e⁻ → Mn²⁺ + 4H₂O
8. Inorganic Chemistry & Periodicity | 无机化学与周期性
Periodicity: The repeating pattern of physical and chemical properties across a period in the Periodic Table. It is explained by the arrangement of electrons in outer shells and effective nuclear charge.
周期性：元素周期表中同一周期内物理和化学性质的重复模式。它可以通过电子在外层壳中的排布和有效核电荷来解释。
First ionisation energy trend: Across a period, first ionisation energy generally increases due to increased nuclear charge and similar shielding, making outer electrons harder to remove. Down a group, it decreases because outer electrons are further from the nucleus and more shielded.
第一电离能趋势：在同一周期中，由于核电荷增加而屏蔽效应相似，第一电离能通常增加，使得外层电子更难移除。在同一族中，由于外层电子离核更远且屏蔽更多，第一电离能降低。
Group 2 elements (alkaline earth metals): Reactive metals that form 2+ ions. Reactivity increases down the group. They react with water to form hydroxides and hydrogen. Magnesium reacts slowly with cold water but vigorously with steam.
第2族元素（碱土金属）：形成 2+ 离子的活泼金属。反应活性沿族向下增加。它们与水反应生成氢氧化物和氢气。镁与冷水反应缓慢，但与水蒸气反应剧烈。
Halogens (Group 17): Diatomic non-metals that act as oxidising agents. Oxidising power decreases down the group (F₂ > Cl₂ > Br₂ > I₂). A more reactive halogen can displace a less reactive one from its halide solution.
卤素（第17族）：作为氧化剂的非金属双原子分子。氧化能力沿族向下减弱（F₂ > Cl₂ > Br₂ > I₂）。较活泼的卤素可从卤化物溶液中置换出较不活泼的卤素。
9. Introduction to Organic Chemistry | 有机化学入门
Homologous series: A family of organic compounds with the same general formula, similar chemical properties, and a gradual trend in physical properties. Each successive member differs by a CH₂ unit. Examples include alkanes, alkenes, and alcohols.
同系列：具有相同通式、相似化学性质且物理性质呈渐变趋势的一系列有机化合物。每个连续成员相差一个 CH₂ 单元。例子包括烷烃、烯烃和醇。
Functional group: An atom or group of atoms within an organic molecule that determines its characteristic chemical reactions. For example, the hydroxyl group (-OH) makes an alcohol, and the carboxyl group (-COOH) makes a carboxylic acid.
官能团：有机分子中决定其特征化学反应的原子或原子团。例如，羟基 (-OH) 使分子成为醇，羧基 (-COOH) 使分子成为羧酸。
Structural formula: A representation that shows the arrangement of atoms in a molecule without drawing all individual bonds, e.g., CH₃CH₂OH for ethanol. It is less detailed than displayed formula but provides connectivity.
结构式：显示分子中原子排列而不画出所有单个键的表示法，例如乙醇的 CH₃CH₂OH。它比展示式简约，但提供了连接关系。
Skeletal formula: A simplified organic formula where carbon atoms are represented by the ends of lines and vertices, and hydrogen atoms attached to carbon are not shown. Functional groups are explicitly drawn. It is widely used in exam questions.
骨架式：一种简化的有机分子式，碳原子用线条的末端和顶点表示，连在碳上的氢原子不显示。官能团要明确画出。它在考试题目中被广泛使用。
Structural isomerism: Compounds with the same molecular formula but different structural arrangement of atoms. There are three types: chain isomerism, position isomerism, and functional group isomerism.
结构异构：分子式相同但原子结构排列不同的化合物。有三种类型：碳链异构、位置异构和官能团异构。
10. Functional Groups & Reactions | 官能团与反应
Alkane: A saturated hydrocarbon containing only C–C single bonds, general formula CₙH₂ₙ₊₂. Alkanes undergo combustion and substitution reactions with halogens in UV light (free-radical substitution).
烷烃：只含有 C–C 单键的饱和烃，通式为 CₙH₂ₙ₊₂。烷烃可发生燃烧反应，以及在紫外光下与卤素的取代反应（自由基取代）。
Alkene: An unsaturated hydrocarbon containing at least one C=C double bond, general formula CₙH₂ₙ. The double bond is a region of high electron density, making alkenes susceptible to electrophilic addition. Major addition reactions include hydrogenation, hydration, and reaction with halogens.
烯烃：含有至少一个 C=C 双键的不饱和烃，通式为 CₙH₂ₙ。双键是高电子密度区域，使烯烃易发生亲电加成。主要的加成反应包括氢化、水合和与卤素的反应。
Alcohol: Contain the hydroxyl (-OH) functional group. Primary alcohols can be oxidised to aldehydes and then to carboxylic acids; secondary alcohols to ketones; tertiary alcohols resist oxidation. Alcohols can undergo dehydration to form alkenes.
醇：含有羟基 (-OH) 官能团。伯醇可被氧化成醛，进一步氧化成羧酸；仲醇氧化为酮；叔醇不易被氧化。醇可发生脱水生成烯烃。
Carboxylic acid: Contains the carboxyl (-COOH) group. They are weak acids that partially dissociate in water. Typical reactions include neutralisation with bases, condensation with alcohols to form esters, and reduction to primary alcohols.
羧酸：含有羧基 (-COOH)。它们是弱酸，在水中部分电离。典型的反应包括与碱的中和反应、与醇缩合生成酯，以及还原成伯醇。
Ester: Formed by the reaction of a carboxylic acid with an alcohol in the presence of an acid catalyst (esterification). Esters have sweet, fruity smells and are used as flavourings and solvents. They can be hydrolysed back to the parent acid and alcohol.
酯：由羧酸与醇在酸催化剂存在下反应（酯化）生成。酯具有甜美的果香，用作调味剂和溶剂。它们可以水解回到原来的酸和醇。
Published by TutorHao | 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