📚 AP Chemistry Core Terminology Summary (Part 1) | AP 化学核心术语汇总（一）
A strong foundation in chemical terminology is crucial for tackling AP Chemistry concepts and problems. This first part of our terminology series covers essential terms from atomic theory to chemical equilibrium, providing clear definitions in both English and Chinese to support bilingual learners. Understanding these core terms will sharpen your ability to interpret exam questions, write precise free-response answers, and engage with advanced topics with confidence.
扎实的化学术语基础对于攻克AP化学概念和问题至关重要。本术语系列的第一部分涵盖了从原子理论到化学平衡的基本术语，并以中英双语提供清晰定义，助力双语学习者。掌握这些核心术语将提升你解读试题、撰写精准主观题答案以及自信地学习进阶专题的能力。
1. Atomic Structure and Subatomic Particles | 原子结构与亚原子粒子
Atom: The smallest unit of an element that retains the chemical properties of that element. It consists of a dense, positively charged nucleus surrounded by a cloud of negatively charged electrons.
原子： 元素的最小单位，保留该元素的化学性质。它由一个致密、带正电的原子核以及环绕其周围的带负电的电子云组成。
Proton: A subatomic particle found in the nucleus with a positive charge (+1) and a relative mass of approximately 1 atomic mass unit (amu). The number of protons defines the element.
质子： 位于原子核内的一种亚原子粒子，带正电荷 (+1)，相对质量约为 1 原子质量单位 (amu)。质子数决定了元素的种类。
Neutron: A neutral subatomic particle located in the nucleus, with a mass slightly larger than that of a proton and no electric charge. Neutrons contribute to the stability of the nucleus and, together with protons, determine the mass number.
中子： 位于原子核内的一种中性亚原子粒子，质量略大于质子，不带电荷。中子有助于原子核的稳定性，并与质子共同决定质量数。
Electron: A negatively charged subatomic particle (-1) that moves around the nucleus within orbitals. Electrons have a negligible mass compared to protons and neutrons and are primarily responsible for chemical bonding and reactions.
电子： 带负电荷 (-1) 的亚原子粒子，在核外轨道上运动。电子的质量与质子和中子相比可忽略不计，它们主要负责化学键合与化学反应。
Atomic Number (Z): The number of protons in the nucleus of an atom. It uniquely identifies an element and determines its position on the periodic table.
原子序数 (Z)： 原子核中的质子数。它唯一地标识一种元素，并决定其在周期表中的位置。
Mass Number (A): The total number of protons and neutrons in an atom’s nucleus. It is always a whole number and is used to distinguish isotopes of an element.
质量数 (A)： 原子核中质子与中子的总数。它总是一个整数，用于区分同一元素的不同同位素。
Isotope: Atoms of the same element (same atomic number) that have different numbers of neutrons and therefore different mass numbers. Isotopes exhibit similar chemical behavior but may differ in physical properties and nuclear stability.
同位素： 具有相同原子序数（相同质子数）但中子数不同、因而质量数不同的同一种元素的原子。同位素表现出相似的化学行为，但在物理性质和核稳定性上可能有所不同。
Electron Configuration: The distribution of electrons in the atomic orbitals of an atom, usually written using the principal quantum number, sublevel letter, and superscript indicating the number of electrons (e.g., 1s² 2s² 2p⁶). It determines the atom’s chemical reactivity.
电子排布： 原子轨道中电子的分布情况，通常用主量子数、亚层字母及表示电子数的上标书写（例如 1s² 2s² 2p⁶）。它决定了原子的化学反应性。
2. Periodic Table and Periodicity | 元素周期表与周期性
Period: A horizontal row in the periodic table. All elements in a period have the same number of electron shells; moving across a period, the chemical properties change gradually as the nuclear charge increases.
周期： 元素周期表中的横排。同一周期的元素拥有相同的电子层数；沿周期从左向右，随着核电荷增加，化学性质逐渐变化。
Group (Family): A vertical column in the periodic table. Elements in the same group share similar valence electron configurations and thus exhibit comparable chemical properties and reactivity trends.
族： 元素周期表中的纵列。同一族元素具有相似的价电子排布，因而表现出可比的化学性质和反应性趋势。
Atomic Radius: A measure of the size of an atom, typically defined as half the distance between the nuclei of two bonded identical atoms. Atomic radius generally decreases across a period and increases down a group.
原子半径： 用于衡量原子大小的量度，通常定义为两个成键同种原子核间距的一半。原子半径通常沿周期从左向右减小，沿族从上向下增大。
Ionization Energy: The minimum energy required to remove the most loosely bound electron from a gaseous atom in its ground state. Successive ionization energies increase, and a large jump indicates removal of a core electron. Ionization energy generally increases across a period and decreases down a group.
电离能： 从处于基态的气态原子中移走最外层一个电子所需的最小能量。逐级电离能递增，出现大幅突变表明开始移走内层电子。电离能通常沿周期从左向右增大，沿族从上向下减小。
Electronegativity: A measure of the tendency of an atom to attract shared electrons in a chemical bond. On the Pauling scale, fluorine is the most electronegative element. Electronegativity increases across a period and decreases down a group.
电负性： 用于衡量原子在化学键中吸引共用电子倾向的量度。在鲍林标度下，氟是电负性最强的元素。电负性沿周期从左向右增大，沿族从上向下减小。
3. Chemical Bonding and Molecular Structure | 化学键与分子结构
Ionic Bond: A type of chemical bond formed by the electrostatic attraction between oppositely charged ions, typically between a metal cation and a nonmetal anion. Ionic compounds generally form crystalline lattices with high melting and boiling points.
离子键： 由带相反电荷离子之间的静电吸引力形成的化学键，通常发生在金属阳离子与非金属阴离子之间。离子化合物一般形成具有高熔点和高沸点的晶体晶格。
Covalent Bond: A chemical bond that involves the sharing of electron pairs between atoms. Covalent bonds can be nonpolar (equal sharing) or polar (unequal sharing), leading to molecular compounds with diverse properties.
共价键： 原子间通过共用电子对形成的化学键。共价键可以是非极性的（均等共用）或极性的（不均等共用），从而形成性质多样的分子化合物。
Lewis Structure: A diagram that represents the arrangement of valence electrons around atoms in a molecule, using dots for electrons and lines for bonds. It helps predict connectivity, bond order, and the presence of lone pairs and formal charges.
路易斯结构： 表示分子中原子周围价电子排列方式的图示，用点表示电子，用线表示键。它有助于预测连接方式、键级以及孤对电子和形式电荷的存在。
Octet Rule: The observation that atoms of main-group elements tend to form bonds so that each atom has eight electrons in its valence shell, achieving a noble gas electron configuration. There are exceptions, such as molecules with an incomplete octet or an expanded octet.
八隅规则： 主族元素的原子倾向于形成化学键，使得每个原子的价层具有八个电子，从而达成稀有气体电子构型的经验规律。存在例外，例如不完整八隅体或扩展八隅体的分子。
VSEPR Theory (Valence Shell Electron Pair Repulsion): A model used to predict the three-dimensional geometry of molecules based on the idea that electron pairs around a central atom repel each other and arrange themselves as far apart as possible. It accounts for molecular shapes such as linear, trigonal planar, tetrahedral, and bent.
价层电子对互斥理论 (VSEPR)： 用于预测分子三维几何构型的模型，其核心观点是中心原子周围的电子对相互排斥，并尽可能彼此远离排列。该理论能够解释直线形、平面三角形、四面体形和弯曲形等分子形状。
Hybridization: The mixing of atomic orbitals to form new hybrid orbitals suitable for the pairing of electrons to form chemical bonds in valence bond theory. Common hybridizations include sp, sp², sp³, sp³d, and sp³d², which correlate with specific molecular geometries.
杂化： 原子轨道的混合，以形成适合电子配对成键的新杂化轨道，用于价键理论。常见的杂化类型包括 sp、sp²、sp³、sp³d 和 sp³d²，它们与特定的分子几何构型相对应。
4. Intermolecular Forces | 分子间作用力
London Dispersion Forces (LDF): Weak intermolecular forces arising from temporary instantaneous dipoles that occur when the electron distribution in an atom or molecule becomes momentarily asymmetric. They are present in all molecules and atoms and increase with molar mass and polarizability.
伦敦色散力 (LDF)： 由于原子或分子中的电子分布瞬间不对称而产生瞬时偶极所导致的微弱分子间作用力。它们存在于所有分子和原子中，并随着摩尔质量和极化率的增大而增强。
Dipole-Dipole Interactions: Attractive forces between the positive end of one polar molecule and the negative end of another polar molecule. These interactions are stronger than dispersion forces for molecules of comparable size and contribute to higher boiling points.
偶极-偶极相互作用： 一个极性分子的正电端与另一极性分子的负电端之间的吸引力。对于分子大小相近的物质，这些相互作用比色散力更强，并导致沸点升高。
Hydrogen Bonding: An exceptionally strong type of dipole-dipole interaction that occurs when hydrogen is covalently bonded to highly electronegative atoms such as nitrogen, oxygen, or fluorine. The hydrogen atom carries a significant partial positive charge and is attracted to a lone pair on another electronegative atom. Hydrogen bonding profoundly influences the properties of water, DNA, and proteins.
氢键： 一种特别强的偶极-偶极相互作用，发生在氢与氮、氧或氟等强电负性原子以共价键结合时。氢原子带显著的部分正电荷，并被另一电负性原子上的孤对电子吸引。氢键深刻影响着水、DNA 和蛋白质的性质。
Ion-Dipole Forces: Attractive forces between an ion (cation or anion) and a polar molecule. These forces are important in solutions of ionic compounds in polar solvents, such as the hydration of ions in water.
离子-偶极力： 离子（阳离子或阴离子）与极性分子之间的吸引力。这些力在离子化合物溶于极性溶剂的溶液中很重要，例如水中离子的水合作用。
5. Stoichiometry | 化学计量学
Mole (mol): The SI base unit for the amount of substance. One mole contains exactly 6.02214076 × 10²³ elementary entities (Avogadro’s number). It provides a bridge between the atomic scale and macroscopic amounts of substances.
摩尔 (mol)： 物质的量的国际单位制基本单位。1 摩尔恰好包含 6.02214076 × 10²³ 个基本单元（阿伏伽德罗常数）。它为原子尺度和宏观物质数量之间架起了桥梁。
Avogadro’s Number (Nₐ): The number of particles (atoms, molecules, ions, etc.) in one mole of substance, approximately 6.022 × 10²³ mol⁻¹. It allows chemists to convert between the number of particles and the amount in moles.
阿伏伽德罗常数 (Nₐ)： 1 摩尔物质中所含的粒子（原子、分子、离子等）数，约为 6.022 × 10²³ mol⁻¹。它使化学工作者能够在粒子数与摩尔量之间进行换算。
Molar Mass (M): The mass of one mole of a substance, expressed in grams per mole (g mol⁻¹). Numerically equal to the average atomic or formula mass in atomic mass units (amu), it is used to convert between mass and moles.
摩尔质量 (M)： 1 摩尔物质的质量，以克每摩尔 (g mol⁻¹) 表示。在数值上等于以原子质量单位 (amu) 表示的平均原子质量或式量，用于在质量和摩尔之间进行换算。
Limiting Reactant: The reactant that is completely consumed in a chemical reaction and thus determines the maximum amount of product that can be formed. The other reactants are present in excess.
限量反应物： 在化学反应中被完全消耗的反应物，因此决定了能够生成产物的最大量。其他反应物则过量存在。
Percent Yield: The ratio of the actual yield (mass of product obtained experimentally) to the theoretical yield (mass predicted by stoichiometry), multiplied by 100%. It measures the efficiency of a reaction.
Percent yield = (actual yield / theoretical yield) × 100%
百分产率： 实际产量（通过实验获得的产品质量）与理论产量（由化学计量学预测的质量）之比，乘以 100%。它衡量反应的效率。
6. Thermochemistry | 热化学
Enthalpy (H): A thermodynamic state function representing the total heat content of a system at constant pressure. The change in enthalpy (ΔH) for a reaction is the heat absorbed or released under constant pressure.
焓 (H)： 表示在恒压条件下系统总热含量的热力学状态函数。反应的焓变 (ΔH) 即为恒压条件下吸收或放出的热量。
Exothermic Reaction: A reaction that releases energy to the surroundings, causing the enthalpy of the system to decrease (ΔH < 0). The products have lower enthalpy than the reactants, and the surroundings typically warm up.
放热反应： 向周围环境释放能量的反应，导致系统的焓减小 (ΔH < 0)。产物的焓低于反应物，环境通常变暖。
Endothermic Reaction: A reaction that absorbs energy from the surroundings, so the system’s enthalpy increases (ΔH > 0). The products are higher in enthalpy than the reactants, and the surroundings may cool down.
吸热反应： 从周围环境吸收能量的反应，系统的焓增加 (ΔH > 0)。产物的焓高于反应物，环境可能冷却。
Specific Heat Capacity (c): The amount of heat required to raise the temperature of one gram of a substance by one degree Celsius (or one kelvin). It is an intensive property used in calorimetry calculations with the relationship q = mcΔT.
比热容 (c)： 使1克物质的温度升高1摄氏度（或1开尔文）所需的热量。它是用于量热计算的强度性质，关系式为 q = mcΔT。
Hess’s Law: The overall enthalpy change for a reaction is the sum of the enthalpy changes for individual steps in a multistep process, regardless of the pathway taken. It allows the calculation of ΔH for reactions that are difficult to measure directly by combining known thermochemical equations.
盖斯定律： 一个反应的总焓变等于多步过程中各步焓变之和，与反应途径无关。利用已知的热化学方程组合，可以计算出难以直接测量的反应的 ΔH。
7. Gases | 气体
Pressure: The force exerted by gas molecules per unit area on the walls of a container. Common units include atmosphere (atm), Pascal (Pa), torr, and mm Hg. Standard pressure is 1 atm = 760 mm Hg = 101.325 kPa.
压强： 气体分子对容器壁单位面积上施加的力。常用单位包括标准大气压 (atm)、帕斯卡 (Pa)、托 (torr) 和毫米汞柱 (mm Hg)。标准压强为 1 atm = 760 mm Hg = 101.325 kPa。
Ideal Gas Law: An equation of state that relates pressure (P), volume (V), amount (n), and temperature (T) for an ideal gas. The law combines Boyle’s, Charles’s, and Avogadro’s laws and is expressed as
PV = nRT
where R is the universal gas constant (e.g., 0.08206 L·atm·mol⁻¹·K⁻¹).
理想气体定律： 将理想气体的压强 (P)、体积 (V)、物质的量 (n) 和温度 (T) 关联起来的状态方程。该定律结合了玻意耳定律、查理定律和阿伏伽德罗定律，表达式为 PV = nRT，其中 R 是通用气体常数（例如 0.08206 L·atm·mol⁻¹·K⁻¹）。
Partial Pressure (Dalton’s Law): In a mixture of non-reacting gases, the total pressure is equal to the sum of the partial pressures of the individual component gases. The partial pressure of a gas is proportional to its mole fraction in the mixture.
Ptotal = P₁ + P₂ + P₃ + …
分压（道尔顿分压定律）： 在不相互反应的气体混合物中，总压强等于各组分气体分压之和。某气体的分压与其在混合物中的摩尔分数成正比。
Kinetic Molecular Theory (KMT): A model that explains the behavior of ideal gases based on several postulates: gas particles are in constant, random motion; the volume of the particles is negligible; collisions are perfectly elastic; and there are no intermolecular forces. KMT provides a microscopic interpretation of temperature and pressure.
气体分子动理论 (KMT)： 基于以下假设解释理想气体行为的模型：气体粒子处于持续无规则运动中；粒子本身的体积可忽略不计；碰撞是完全弹性的；不存在分子间作用力。该理论为温度和压强提供了微观解释。
8. Solutions and Concentration | 溶液与浓度
Solute: The substance that is dissolved in a solvent to form a solution. It is typically present in a smaller amount and can be a solid, liquid, or gas.
溶质： 溶解在溶剂中形成溶液的物质。通常含量较少，可以是固体、液体或气体。
Solvent: The medium that dissolves the solute, making up the majority of the solution. Water is known as the ‘universal solvent’ due to its ability to dissolve many ionic and polar substances.
溶剂： 溶解溶质的介质，构成溶液的大部分。水因其能溶解许多离子和极性物质而被称作“万能溶剂”。
Molarity (M): A concentration unit defined as the number of moles of solute per liter of solution (mol/L). It is temperature-dependent because volume changes with temperature. Molarity is the most commonly used unit in stoichiometric calculations involving solutions.
物质的量浓度（摩尔浓度，M）： 定义为每升溶液中溶质的摩尔数 (mol/L)。由于体积随温度变化，因此它具有温度依赖性。摩尔浓度是涉及溶液的化学计量计算中最常用的单位。
Dilution: The process of reducing the concentration of a solution by adding more solvent. The number of moles of solute remains constant, so the relationship M₁V₁ = M₂V₂ is used to calculate new concentrations or volumes.
稀释： 通过加入更多溶剂来降低溶液浓度的过程。溶质的摩尔数保持不变，因此利用 M₁V₁ = M₂V₂ 的关系式计算新的浓度或体积。
Solubility: The maximum amount of a solute that can dissolve in a given amount of solvent at a specified temperature and pressure to form a saturated solution. Solubility is influenced by temperature, pressure (for gases), and the nature of solute-solvent interactions (‘like dissolves like’).
溶解度： 在特定温度和压强下，一定量溶剂中能够溶解形成饱和溶液的溶质最大量。溶解度受温度、压强（对气体而言）以及溶质-溶剂相互作用性质（“相似相溶”）的影响。
9. Chemical Kinetics | 化学动力学
Rate of Reaction: The change in concentration of a reactant or product per unit time. It is usually expressed in mol·L⁻¹·s⁻¹ and can be measured as the decrease in reactant concentration or the increase in product concentration over time.
反应速率： 单位时间内反应物或产物浓度的变化。通常以 mol·L⁻¹·s⁻¹ 表示，可以通过测量反应物浓度随时间的减少或产物浓度随时间的增加来获得。
Activation Energy (Eₐ): The minimum kinetic energy that colliding reactant molecules must possess for a chemical reaction to occur. It represents the energy barrier between reactants and products and can be lowered by a catalyst.
活化能 (Eₐ)： 碰撞的反应物分子发生化学反应所必须具备的最小动能。它代表了反应物和产物之间的能垒，催化剂可以降低活化能。
Catalyst: A substance that increases the rate of a reaction without being consumed in the overall process. A catalyst works by providing an alternative reaction pathway with a lower activation energy. Homogeneous catalysts are in the same phase as the reactants, while heterogeneous catalysts are in a different phase.
催化剂： 能加快反应速率而在总过程中自身不被消耗的物质。催化剂通过提供具有较低活化能的替代反应途径起作用。均相催化剂与反应物处于同一相，多相催化剂则处于不同相。
Rate Law: An equation that relates the reaction rate to the concentrations of reactants raised to some powers (orders). For a generic reaction aA + bB → products, the rate law is often Rate = k[A]ᵐ[B]ⁿ, where k is the rate constant, and m and n are the reaction orders determined experimentally.
速率方程： 将反应速率与反应物浓度的若干次幂（级数）联系起来的方程。对于通用反应 aA + bB → 产物，速率方程通常为 Rate = k[A]ᵐ[B]ⁿ，其中 k 是速率常数，m 和 n 是由实验确定的反应级数。
Reaction Intermediate: A species that is formed in one elementary step of a reaction mechanism and consumed in a subsequent step. Intermediates appear in the mechanism but do not appear in the overall balanced equation.
反应中间体： 在反应机理的某一步基元反应中生成，并在后续步骤中被消耗的物种。中间体出现在机理中，但不出现于总的配平方程式中。
10. Chemical Equilibrium | 化学平衡
Dynamic Equilibrium: A state in a reversible chemical reaction where the rate of the forward reaction equals the rate of the reverse reaction, resulting in no net change in the concentrations of reactants and products. The system is dynamic because both reactions continue to occur at the molecular level.
动态平衡： 可逆化学反应中，正反应速率与逆反应速率相等、从而使反应物和产物的浓度保持净不变的状态。该体系是动态的，因为两种反应在分子水平上仍在持续进行。
Equilibrium Constant (K): A numerical value that expresses the ratio of product concentrations to reactant concentrations at equilibrium, each raised to the power of its stoichiometric coefficient. For the reaction aA + bB ⇌ cC + dD, the equilibrium constant expression is
Kc = [C]ᶜ[D]ᵈ / ([A]ᵃ[B]ᵇ)
The value of K depends on temperature and indicates the extent to which a reaction proceeds toward products.
平衡常数 (K)： 表示平衡时产物浓度与反应物浓度之比的数值，各浓度以计量系数为指数乘方。对于反应 aA + bB ⇌ cC + dD，平衡常数表达式为 Kc = [C]ᶜ[D]ᵈ / ([
Published by TutorHao | AP 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