📚 Year 10 WJEC Chemistry: Core Knowledge Review | Year 10 WJEC化学：核心知识点梳理
Year 10 WJEC Chemistry builds the essential foundation for understanding the material world. From the inner workings of atoms to the energy changes driving reactions, this stage introduces the core principles that explain the behaviour of substances. This article provides a structured overview of the key topics covered during the first year of the GCSE course, helping you consolidate your learning and prepare for assessments effectively.
Year 10 WJEC 化学课程为学生理解物质世界奠定了重要基础。从原子的内部结构到驱动反应的能量变化，这一年将介绍解释物质行为的核心原理。本文对GCSE课程第一年涵盖的关键主题进行了系统梳理，帮助你巩固所学内容，有效备考。
1. Atomic Structure | 原子结构
All matter is made up of atoms, which consist of a central nucleus containing protons and neutrons, surrounded by electrons moving in shells. The number of protons determines the element and is called the atomic number, while the total number of protons and neutrons gives the mass number.
所有物质都由原子构成，原子中心有一个由质子和中子组成的原子核，核外有电子按壳层排布运动。质子数决定了元素的种类，称为原子序数；质子数与中子数之和则为质量数。
Atoms are electrically neutral because the number of protons equals the number of electrons. Ions form when atoms gain or lose electrons, resulting in a net charge. For example, a sodium atom loses one electron to form Na⁺, while a chlorine atom gains one electron to form Cl⁻.
原子呈电中性，因为质子数等于电子数。当原子得到或失去电子时，会形成带有净电荷的离子。例如，钠原子失去一个电子形成 Na⁺，而氯原子得到一个电子形成 Cl⁻。
Isotopes are atoms of the same element that have different numbers of neutrons, hence the same atomic number but different mass numbers. They have identical chemical properties but different physical properties, such as density and rate of diffusion.
同位素是指同一种元素中具有不同中子数的原子，它们具有相同的原子序数但不同的质量数。它们的化学性质相同，但物理性质（如密度和扩散速率）有所差异。
2. The Periodic Table | 元素周期表
Elements are arranged in the periodic table in order of increasing atomic number. The vertical columns are called groups, and elements in the same group have similar chemical properties because they have the same number of electrons in their outermost shell. The horizontal rows are periods, and across a period the number of outer electrons increases gradually.
元素在周期表中按原子序数递增的顺序排列。纵列称为族，同一族的元素具有相似的化学性质，因为它们的最外层电子数相同。横排称为周期，同一周期内元素的最外层电子数逐渐增加。
Group 1 elements, the alkali metals, have one outer electron and become more reactive as you move down the group because the outer electron is further from the nucleus and more easily lost. Group 7 halogens have seven outer electrons and become less reactive down the group, as the attraction for an extra electron weakens with increasing atomic size.
第1族元素是碱金属，最外层只有一个电子，从上到下活泼性逐渐增强，因为最外层电子离核更远，更容易丢失。第7族卤素最外层有七个电子，从上到下活泼性递减，因为随着原子半径增大，原子核对外来电子的吸引力减弱。
Group 0 noble gases are inert because they already have a full outer electron shell, making them stable and unreactive. Transition metals are found in the central block and form coloured compounds, often act as catalysts, and can have multiple oxidation states.
第0族稀有气体具有惰性，因为它们已经具有稳定的满壳层电子结构，不易发生反应。过渡金属位于周期表中部区域，能形成有色化合物，常作为催化剂使用，并具有多种氧化态。
3. Ionic Bonding | 离子键
Ionic bonding occurs between a metal and a non-metal. The metal atom loses electrons to form a positive cation, while the non-metal atom gains electrons to form a negative anion. The strong electrostatic attraction between oppositely charged ions holds the giant ionic lattice together.
离子键形成于金属与非金属之间。金属原子失去电子形成带正电的阳离子，非金属原子得到电子形成带负电的阴离子。带相反电荷的离子之间强烈的静电引力将巨大的离子晶格结合在一起。
Ionic compounds form a regular array called a giant ionic lattice, where each ion is surrounded by ions of opposite charge. This structure explains their properties: they have high melting and boiling points, do not conduct electricity when solid (as ions are fixed in place), but conduct when molten or dissolved in water because the ions are free to move.
离子化合物形成规则的阵列，称为巨型离子晶格，每个离子被相反电荷的离子包围。这种结构决定了它们的性质：熔点和沸点高，固态时不导电（因为离子被固定在晶格中），但熔融态或溶于水时能够导电，因为离子可以自由移动。
4. Covalent Bonding | 共价键
Covalent bonding occurs between two non-metal atoms, which share pairs of electrons to achieve a stable outer electron arrangement. Each shared pair of electrons forms one covalent bond, and molecules can contain single, double or triple bonds depending on the number of shared pairs.
共价键形成于两个非金属原子之间，它们通过共享电子对来达到稳定的最外层电子排布。每一对共用电子形成一根共价键，分子中可根据共用电子对的数目含有单键、双键或三键。
Simple covalent molecules, such as water (H₂O), carbon dioxide (CO₂) and methane (CH₄), have strong covalent bonds within the molecule but only weak intermolecular forces between molecules. This gives them low melting and boiling points, and they do not conduct electricity because they have no overall charge and no free ions or electrons.
简单共价分子，如水 (H₂O)、二氧化碳 (CO₂) 和甲烷 (CH₄)，分子内部有很强的共价键，但分子之间仅存在微弱的分子间作用力。这使得它们的熔点和沸点较低，而且不导电，因为它们没有整体电荷，也没有可自由移动的离子或电子。
Giant covalent structures, on the other hand, have a vast network of covalent bonds throughout the whole structure. Diamond, a form of carbon, has each carbon atom bonded to four others tetrahedrally, making it extremely hard and giving it a very high melting point. Graphite consists of layers of carbon atoms that can slide over each other, so it is soft and conducts electricity due to delocalised electrons between layers.
另一方面，巨型共价结构在整个结构内具有庞大的共价键网络。金刚石是碳的一种形式，每个碳原子与四个其他碳原子以四面体方式成键，这使其极为坚硬，熔点极高。石墨由碳原子层构成，层间可以滑动，因此质软，并且由于层间存在离域电子而能导电。
5. Metallic Bonding | 金属键
Metallic bonding is the attraction between a lattice of positive metal ions and a ‘sea’ of delocalised electrons that are free to move throughout the metal structure. This bonding model explains the characteristic physical properties of metals.
金属键是金属阳离子晶格与可在整个金属结构中自由移动的“离域电子海”之间的吸引力。这种键合模型解释了金属典型的物理性质。
Metals are excellent conductors of electricity and heat because the delocalised electrons can carry charge and energy quickly. They are malleable and ductile—meaning they can be hammered into shape or drawn into wires—because the layers of ions can slide past each other without breaking the metallic bonding. The strength of metallic bonding increases with the charge of the metal ion and the number of delocalised electrons, leading to higher melting points.
金属是电和热的优良导体，因为离域电子能快速传递电荷和能量。它们具有延展性和展性——可以被锤打成薄片或拉成细丝——因为离子层可以相对滑动而不破坏金属键。金属键的强度随金属离子电荷和离域电子数的增加而增强，导致熔点升高。
6. Chemical Formulae and Equations | 化学式与方程式
A chemical formula shows the number and type of atoms in a substance. For ionic compounds, the formula gives the simplest ratio of ions that results in a neutral overall charge. For example, magnesium chloride is MgCl₂ because one Mg²⁺ ion balances two Cl⁻ ions.
化学式表示物质中原子的种类和数量。对于离子化合物，化学式给出能形成电中性整体的最简单离子整数比。例如，氯化镁的化学式为 MgCl₂，因为一个 Mg²⁺ 离子需要两个 Cl⁻ 离子来平衡电荷。
Word equations use the names of reactants and products, while symbol equations use chemical formulae to represent the same change. Balancing a symbol equation is essential to obey the law of conservation of mass—the number of atoms of each element must be equal on both sides of the arrow.
文字方程式使用反应物和生成物的名称，而符号方程式则用化学式来表示相同的变化。配平符号方程式是遵循质量守恒定律所必需的——箭头两边每种元素的原子数必须相等。
2H₂ + O₂ → 2H₂O
State symbols are often added in brackets to indicate the physical state of each substance: (s) for solid, (l) for liquid, (g) for gas and (aq) for aqueous solution, meaning dissolved in water.
通常会添加状态符号来表示每种物质的物理状态：(s) 表示固体，(l) 表示液体，(g) 表示气体，(aq) 表示水溶液，即溶于水。
7. Relative Masses and the Mole | 相对质量与摩尔
The relative atomic mass (Aᵣ) of an element is the average mass of an atom, taking into account the abundance of its isotopes, compared to 1/12th the mass of a carbon‑12 atom. The relative formula mass (Mᵣ) of a compound is the sum of the relative atomic masses of all the atoms in its formula.
元素的相对原子质量 (Aᵣ) 是指一个原子的平均质量（考虑其同位素丰度）与一个碳‑12原子质量的 1/12 的比值。化合物的相对式量 (Mᵣ) 是其化学式中所有原子的相对原子质量之和。
The mole is the unit for amount of substance. One mole of any substance contains 6.02 × 10²³ particles (Avogadro’s constant) and has a mass equal to its relative formula mass in grams. The number of moles (n) can be calculated using:
摩尔是物质的量的单位。一摩尔任何物质都含有 6.02 × 10²³ 个微粒（阿伏伽德罗常数），其质量等于以克为单位的相对式量。物质的量 (n) 可通过下式计算：
n = mass (g) ÷ Mᵣ
This relationship is fundamental for quantitatively analyzing reactions. You can also use it to calculate concentration (c = n ÷ volume in dm³) or to find reacting masses using balanced equations.
这一关系是定量分析反应的基础。你还可以用它来计算浓度 (c = n ÷ 体积 dm³) 或利用配平的方程式求出参加反应的质量。
8. Acids, Bases and Neutralisation | 酸、碱与中和反应
Acids are substances that release hydrogen ions (H⁺) in aqueous solution. Common laboratory acids include hydrochloric acid (HCl), sulfuric acid (H₂SO₄) and nitric acid (HNO₃). Bases are substances that neutralise acids, and alkalis are soluble bases that release hydroxide ions (OH⁻) in water.
酸是在水溶液中能释放氢离子 (H⁺) 的物质。常见的实验室酸有盐酸 (HCl)、硫酸 (H₂SO₄) 和硝酸 (HNO₃)。碱是能中和酸的物质，而可溶性碱在水溶液中能释放氢氧根离子 (OH⁻)。
The pH scale measures the acidity or alkalinity of a solution: pH values below 7 indicate an acidic solution, pH 7 is neutral, and values above 7 indicate an alkaline solution. Universal indicator and pH probes can be used to determine pH.
pH 标度用于衡量溶液的酸碱度：pH 值小于 7 表示酸性溶液，pH 等于 7 为中性，大于 7 表示碱性溶液。可使用通用指示剂或 pH 计来测定 pH 值。
During neutralisation, H⁺ ions from the acid react with OH⁻ ions from the alkali to produce water:
在中和反应过程中，酸中的 H⁺ 离子与碱中的 OH⁻ 离子反应生成水：
H⁺ + OH⁻ → H₂O
This reaction forms a salt and water. For instance, hydrochloric acid reacts with sodium hydroxide to give sodium chloride and water. Soluble salts can be made by reacting an acid with a metal, a metal oxide, a metal hydroxide or a metal carbonate.
该反应生成盐和水。例如，盐酸与氢氧化钠反应生成氯化钠和水。可溶性盐可通过酸与金属、金属氧化物、金属氢氧化物或金属碳酸盐反应制得。
9. Electrolysis | 电解
Electrolysis is the process of using direct electric current to break down an ionic compound into its elements. It requires an electrolyte—the molten or dissolved ionic compound—and two electrodes connected to a power supply. The positive electrode is the anode, and the negative electrode is the cathode.
电解是利用直流电将离子化合物分解为组成元素的过程。它需要一个电解质——即熔融或溶解状态的离子化合物——以及两根与电源相连的电极。正极为阳极，负极为阴极。
During electrolysis, positive cations move towards the cathode and gain electrons (reduction), while negative anions move towards the anode and lose electrons (oxidation). For example, in the electrolysis of molten lead(II) bromide, lead metal forms at the cathode and bromine gas forms at the anode.
电解过程中，阳离子向阴极移动并得到电子（还原），阴离子向阳极移动并失去电子（氧化）。例如，电解熔融溴化铅(II) 时，铅金属在阴极生成，溴气在阳极生成。
In aqueous solutions, the presence of water complicates the products. At the cathode, if the metal is more reactive than hydrogen, hydrogen gas is produced; otherwise the metal is deposited. At the anode, oxygen is produced unless the solution contains a halide ion, in which case the halogen is discharged.
在水溶液中，水的存在使产物变得复杂。在阴极，如果金属比氢活泼，则产生氢气；否则金属会析出。在阳极，通常会生成氧气，除非溶液中含有卤素离子，此时对应卤素会放电析出。
10. Energy Changes in Reactions | 反应中的能量变化
Chemical reactions are always accompanied by energy changes. Exothermic reactions release heat energy to the surroundings, causing a temperature rise. Examples include combustion, respiration and neutralisation. Endothermic reactions absorb heat energy from the surroundings, causing a temperature drop; examples include thermal decomposition and photosynthesis.
化学反应总伴随着能量变化。放热反应向周围环境释放热量，导致温度升高。例子包括燃烧、呼吸作用和中和反应。吸热反应从周围环境中吸收热量，导致温度降低；例子包括热分解和光合作用。
Energy changes can be represented using reaction profile diagrams, which show the energy of reactants and products. In an exothermic reaction, the products have less energy than the reactants, whereas in an endothermic reaction the products have more energy. The activation energy is the minimum energy needed for a reaction to begin.
能量变化可用反应剖面图表示，图中显示反应物和生成物的能量。在放热反应中，生成物的能量比反应物低；而在吸热反应中，生成物的能量比反应物高。活化能是指反应开始所需的最低能量。
Bond breaking requires energy and is endothermic, while bond making releases energy and is exothermic. The overall energy change of a reaction depends on the balance between these two processes.
断开化学键需要能量，是吸热过程；形成化学键则释放能量，是放热过程。反应总体的能量变化取决于这两个过程之间的平衡。
11. Rates of Reaction | 反应速率
The rate of a chemical reaction measures how quickly reactants are converted into products. It can be followed by monitoring changes such as the volume of gas produced, loss of mass, colour change or formation of a precipitate.
化学反应速率衡量反应物转化为生成物的快慢。可以通过监测气体产量、质量损失、颜色变化或沉淀生成等变化来追踪反应进程。
Several factors affect the rate: increasing the temperature gives particles more kinetic energy, making them move faster and collide more frequently and with greater energy, so more collisions exceed the activation energy. Increasing the concentration of a solution or the pressure of reacting gases also increases the number of particles in a given volume, leading to more frequent collisions.
影响速率的主要因素有：升高温度使粒子动能增大，运动加快，碰撞更频繁且碰撞能量更高，因此超过活化能的碰撞增多。增大溶液浓度或反应气体的压强也会增加给定体积内的粒子数，从而导致碰撞更加频繁。
Using a solid reactant in smaller pieces (greater surface area) increases the rate because more particles are exposed and available to collide. A catalyst speeds up a reaction by providing an alternative pathway with a lower activation energy, without being used up in the process.
使用小颗粒固体反应物（增大表面积）会提高速率，因为有更多的粒子暴露在外并能参与碰撞。催化剂通过提供一条活化能较低的替代路径来加快反应，而自身在过程中不被消耗。
12. Separation Techniques: Chromatography | 分离技术：色谱法
Chromatography is a technique used to separate and identify components of a mixture, often coloured substances such as inks and food dyes. It works because different components have differing solubilities in a solvent and different affinities for the stationary phase (the chromatography paper).
色谱法是一种用于分离和鉴定混合物成分的技术，常应用于墨水、食用色素等有色物质。它的工作原理是不同成分在溶剂中的溶解度不同，且对固定相（色谱纸）的亲和力也不同。
In paper chromatography, a spot of the mixture is placed on a pencil baseline near the bottom of the paper, and the paper is suspended in a solvent with the baseline above the solvent level. As the solvent travels up the paper, the components are carried at different rates and separate into spots.
在纸色谱法中，将混合物点在靠近纸底部的铅笔基线上，然后将纸悬挂在溶剂中，基线必须高于溶剂液面。随着溶剂沿纸上升，各成分以不同速率移动，从而分离成不同的斑点。
The retention factor (Rf value) is used to identify a substance and is calculated as:
比移值 (Rf 值) 用于鉴定物质，计算公式为：
Rf = distance moved by substance ÷ distance moved by solvent front
Each substance has a characteristic Rf value under the same conditions, making chromatography useful for forensic or food analysis.
在相同条件下，每种物质都有其特征 Rf 值，这使得色谱法在法医鉴定或食品分析中具有实用价值。
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