📚 Year 11 WJEC Science: Core Knowledge Review | Year 11 WJEC 科学：核心知识点梳理
This article consolidates the essential knowledge required for the WJEC GCSE Science (Double Award) specification. It covers key concepts from Biology, Chemistry and Physics, designed to support Year 11 students in their revision. Each section presents facts, processes and equations you must know, with paired explanations in Chinese to reinforce understanding.
本文梳理了 WJEC GCSE 科学（双奖）的核心知识点，涵盖生物、化学和物理中最重要的概念，帮助 Year 11 学生高效复习。每个部分都给出必知的事实、过程和方程式，并配以中文解释，强化双语理解。
1. Cells, Organisation, Enzymes and Bioenergetics | 细胞、组织、酶与生物能
All living organisms are made of cells. Animal cells contain a nucleus, cytoplasm, cell membrane, mitochondria and ribosomes. Plant cells also have a cell wall, a permanent vacuole and chloroplasts. The nucleus holds DNA, mitochondria carry out aerobic respiration, and ribosomes synthesise proteins.
所有生物都由细胞构成。动物细胞含有细胞核、细胞质、细胞膜、线粒体和核糖体。植物细胞还有细胞壁、永久液泡和叶绿体。细胞核储存 DNA，线粒体进行有氧呼吸，核糖体负责合成蛋白质。
Enzymes are biological catalysts made of protein. Their active site has a specific shape that fits the substrate. The 'lock and key' model describes this. Enzyme activity is affected by temperature and pH; extreme conditions can cause denaturation, changing the shape of the active site permanently.
酶是蛋白质构成的生物催化剂。其活性位点具有特定形状，与底物匹配，“锁与钥匙”模型描述了这种专一性。酶活性受温度和 pH 影响；极端条件可导致变性，永久改变活性位点的形状。
id; in yeast, it produces ethanol and carbon dioxide (fermentation). Photosynthesis converts light energy into chemical energy: 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂. Light intensity, carbon dioxide concentration and temperature are limiting factors.
有氧呼吸从葡萄糖释放能量：葡萄糖 + 氧气 → 二氧化碳 + 水。动物的无氧呼吸产生乳酸；酵母的无氧呼吸则产生乙醇和二氧化碳（发酵）。光合作用将光能转为化学能：6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂。光照强度、二氧化碳浓度和温度是限制因素。
Photosynthesis: 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂
2. Human Systems and Health | 人体系统与健康
The digestive system breaks down large food molecules. Carbohydrases (e.g. amylase) digest starch into sugars; proteases digest proteins into amino acids; lipases digest lipids into fatty acids and glycerol. Bile, produced by the liver, emulsifies fats and neutralises stomach acid.
消化系统分解大分子食物。碳水化合物酶（如淀粉酶）将淀粉消化为糖；蛋白酶将蛋白质消化为氨基酸；脂肪酶将脂类消化为脂肪酸和甘油。肝脏分泌的胆汁能乳化脂肪并中和胃酸。
The circulatory system consists of the heart, blood vessels and blood. The heart has four chambers: left and right atria and ventricles. Arteries carry blood away from the heart; veins carry blood back; capillaries allow exchange of substances. Red blood cells contain haemoglobin for oxygen transport; white blood cells fight pathogens; platelets help clotting.
循环系统由心脏、血管和血液组成。心脏有四个腔室：左心房、左心室、右心房、右心室。动脉将血液带离心脏；静脉将血液送回心脏；毛细血管实现物质交换。红细胞含血红蛋白运输氧气；白细胞抵御病原体；血小板帮助凝血。
Pathogens such as bacteria, viruses and fungi cause disease. The body's first lines of defence include skin and mucus. White blood cells ingest pathogens, produce antibodies and antitoxins. Vaccination involves introducing a dead or weakened pathogen to stimulate antibody production, resulting in immunity. Antibiotics kill bacteria but not viruses.
细菌、病毒和真菌等病原体导致疾病。身体的第一道防线包括皮肤和粘液。白细胞吞噬病原体，产生抗体和抗毒素。疫苗接种通过引入灭活或减毒的病原体刺激抗体生产，从而形成免疫力。抗生素能杀死细菌，但对病毒无效。
(muscle or gland). At a synapse, chemicals called neurotransmitters cross the gap to continue the impulse.
神经系统协调反应。反射弧的路径为：刺激 → 感受器 → 感觉神经元 → 中间神经元（中枢神经系统） → 运动神经元 → 效应器（肌肉或腺体）。在突触处，称为神经递质的化学物质穿过间隙，传递冲动。
3. Genetics, Variation and Ecosystems | 遗传、变异与生态系统
DNA is a double helix polymer made of nucleotides. A gene is a segment of DNA that codes for a protein. In mitosis, cells divide to produce two genetically identical diploid daughter cells for growth and repair. In meiosis, four genetically varied haploid gametes are produced.
DNA 是双螺旋结构的核苷酸聚合物。基因是编码蛋白质的一段 DNA。有丝分裂产生两个遗传上完全相同的二倍体子细胞，用于生长和修复。减数分裂则产生四个遗传组成不同的单倍体配子。
Alleles are different versions of a gene. In a monohybrid cross, if both parents are heterozygous (e.g. Bb), the offspring genotype ratio is typically 1 BB : 2 Bb : 1 bb. The phenotype depends on dominance. Variation within a species can be genetic, environmental, or both. Natural selection states that individuals with advantageous characteristics are more likely to survive and reproduce, passing on favoured alleles.
等位基因是同一基因的不同形式。在单基因杂交中，若双亲均为杂合（如 Bb），子代基因型比例通常为 1 BB : 2 Bb : 1 bb，表型则取决于显隐性关系。物种内的变异可以是遗传的、环境的或两者兼有。自然选择指出，拥有有利特征的个体更可能存活并繁殖，将优势等位基因传递下去。
In ecosystems, energy flows from producers through food chains to consumers. Biomass pyramids show the dry mass at each trophic level. Carbon cycles through photosynthesis, respiration, feeding, decomposition and combustion. The water cycle involves evaporation, condensation, precipitation and transpiration. Human activities such as deforestation and burning fossil fuels increase atmospheric CO₂, contributing to global warming.
在生态系统中，能量从生产者通过食物链流向消费者。生物量金字塔表示各营养级的干重。碳通过光合作用、呼吸、摄食、分解和燃烧循环。水循环包括蒸发、凝结、降水和蒸腾。砍伐森林和燃烧化石燃料等人类活动增加了大气中的 CO₂，加剧全球变暖。
4. Atoms, Periodic Table and Bonding | 原子、元素周期表与化学键
Atoms consist of protons (+1 charge, mass ~1), neutrons (0 charge, mass ~1) and electrons (−1 charge, negligible mass). The atomic number equals the number of protons; the mass number is protons plus neutrons. Isotopes are atoms of the same element with different numbers of neutrons.
原子由质子（带+1电荷，质量≈1）、中子（0电荷，质量≈1）和电子（−1电荷，质量可忽略）构成。原子序数等于质子数；质量数等于质子数加中子数。同位素是同种元素原子，中子数不同。
Electrons occupy shells (energy levels): 2, 8, 8 for the first three shells. Elements in the same group of the periodic table have the same number of outer-shell electrons and therefore similar chemical properties. Group 1 metals are alkali metals; Group 7 are halogens; Group 0 are noble gases with full outer shells.
电子占据电子层（能级）：前三层最多可容纳 2, 8, 8 个电子。同族元素最外层电子数相同，因而化学性质相似。第1族是碱金属；第7族是卤素；第0族是稀有气体，具有满壳层结构。
Ionic bonding occurs between metals and non-metals, involving electron transfer to form cations and anions held by strong electrostatic forces. Covalent bonding occurs between non-metals via shared pairs of electrons. Simple covalent molecules (e.g. H₂O, CO₂) have low melting points; giant covalent structures (e.g. diamond, graphite, SiO₂) are hard and have high melting points. Metallic bonding is a lattice of positive ions in a sea of delocalised electrons, explaining conductivity and malleability.
离子键存在于金属与非金属间，通过电子转移形成阳离子和阴离子，由强静电吸引力结合。共价键存在于非金属间，通过共用电子对形成。简单共价分子（如 H₂O, CO₂）熔点低；巨型共价结构（如金刚石、石墨、SiO₂）坚硬且熔点高。金属键是阳离子浸在离域电子“海洋”中的晶格，这解释了金属的导电性和延展性。
5. Quantitative Chemistry, Acids and Electrolysis | 定量化学、酸与电解
Relative atomic mass (Aᵣ) compares the mass of an atom with 1/12 of carbon‑ icles. Mass (g) = moles × Mᵣ. Using balanced equations, you can calculate reacting masses.
相对原子质量（Aᵣ）是以碳‑12 的 1/12 为基准比较原子质量。相对式量（Mᵣ）是化学式中所有原子的 Aᵣ 总和。摩尔是物质的量的单位；1 摩尔含 6.02 × 10²³ 个微粒。质量 (g) = 摩尔数 × Mᵣ。利用配平的方程式，可以计算反应的质量。
Making pure dry soluble salts requires reacting an acid with an insoluble base, then filtration and crystallisation.
酸在水中产生 H⁺ 离子；碱产生 OH⁻ 离子。pH 值范围从 0（强酸）到 14（强碱）。中和反应：H⁺ + OH⁻ → H₂O。制备纯净、干燥的可溶盐需要用酸与不溶性碱反应，然后过滤并结晶。
Electrolysis splits ionic compounds using direct current. In molten electrolysis, cations move to the cathode (reduction) and anions move to the anode (oxidation). In aqueous electrolysis, water may also be discharged. For example, electrolysis of brine (NaCl solution) produces hydrogen, chlorine and sodium hydroxide.
电解利用直流电分解离子化合物。熔融电解时，阳离子移向阴极（还原），阴离子移向阳极（氧化）。在溶液电解中，水也可能参与放电。例如，电解盐水（NaCl 溶液）可产生氢气、氯气和氢氧化钠。
Neutralisation: H⁺(aq) + OH⁻(aq) → H₂O(l)
6. Rates, Energy and Organic Chemistry | 反应速率、能量与有机化学
Collision theory states that reactions occur when particles collide with sufficient energy (activation energy) and correct orientation. Increasing temperature, concentration, surface area, or adding a catalyst increases the rate by boosting collision frequency or the proportion of successful collisions.
碰撞理论指出，颗粒以足够的能量（活化能）和正确的方向碰撞时，反应才能发生。升高温度、增大浓度、增加表面积或加入催化剂可提高碰撞频率或有效碰撞的比例，从而加快反应速率。
Some reactions are exothermic (release heat, ΔH negative) and others are endothermic (absorb heat, ΔH positive). Reaction profiles show energy changes; the catalyst lowers activation energy by providing an alternative pathway. Reversible reactions reach dynamic equilibrium in a closed system; the position shifts according to Le Chatelier's principle if conditions change.
一些反应是放热的（释放热量，ΔH 为负），另一些是吸热的（吸收热量，ΔH 为正）。反应能量图展示能量变化；催化剂通过提供替代路径降低活化能。可逆反应在封闭系统中达到动态平衡；若条件改变，平衡位置根据勒夏特列原理发生移动。
bustion of hydrocarbons produces CO₂ and water; incomplete combustion produces CO and soot. Alkenes are more reactive than alkanes due to the C=C double bond. Addition polymerisation joins many alkene monomers to form a polymer such as poly(ethene). Condensation polymers require two different functional groups and produce a small molecule like water.
原油是烃类混合物，通过分馏分离。较轻的馏分沸点较低。烃类完全燃烧产生 CO₂ 和水；不完全燃烧产生 CO 和碳粒。烯烃因含有 C=C 双键而比烷烃更活泼。加成聚合将许多烯烃单体连接成聚合物，如聚（乙烯）。缩合聚合需要两种不同官能团，并生成小分子如水和醇。
7. Forces, Motion and Energy | 力、运动与能量
acement, force). Speed = distance ÷ time. Acceleration = change in velocity ÷ time. Newton' resultant force = mass × acceleration (F = m a). In equilibrium, resultant force is zero.
标量只有大小（如速率、距离、质量）；矢量具有大小和方向（如速度、位移、力）。速率 = 距离 ÷ 时间。加速度 = 速度变化 ÷ 时间。牛顿第二定律：合力 = 质量 × 加速度 (F = m a)。物体平衡时，合力为零。
and stored; efficiency = useful output / total input. Conservation of energy states energy cannot be created or destroyed, only transferred.
做功 = 力 × 沿力方向移动的距离。动能 = ½ m v²；重力势能 = m g h。能量可传递和储存；效率 = 有用的输出 / 总输入。能量守恒定律指出，能量不能被创造或消灭，只能被转化。
pends on speed, mass, road conditions and tyre condition. Momentum = mass × velocity. In a collision, momentum is conserved, and safety features like airbags increase impact time to reduce force.
刹车距离 = 反应距离 + 制动距离。反应距离受速度、酒精和注意力影响；制动距离取决于速度、质量、路面状况和轮胎状态。动量 = 质量 × 速度。碰撞中动量守恒；安全气囊等装置通过延长冲击时间减小受力。
F = m a | W = F d | KE = ½ m v²
8. Waves, Radiation, Electricity and Magnetism | 波、辐射、电与磁
ansfer; longitudinal waves (e.g. sound) oscillate parallel. Wave speed = frequency × wavelength (v = f λ). Refraction occurs at boundaries, and total internal reflection can happen if the angle exceeds the critical angle.
波传递能量而不传递物质。横波（如光、电磁波）振动方向与传播方向垂直；纵波（如声波）振动方向与传播方向平行。波速 = 频率 × 波长 (v = f λ)。折射发生在界面处，若入射角大于临界角，可发生全内反射。
The electromagnetic spectrum, in order of increasing frequency, includes radio, microwave, infrared, visible, ultraviolet, X‑rays and gamma rays. All travel at the speed of light in a vacuum. Gamma rays and X‑rays are ionising, making them dangerous to living tissues but useful for medical imaging and treatment.
电磁波谱按频率递增依次为：无线电波、微波、红外线、可见光、紫外线、X 射线和 γ 射线，它们在真空中均以光速传播。γ 射线和 X 射线具有电离能力，对活体组织有害，但在医学成像和治疗中很有用。
Radioactive decay: alpha particles (helium nuclei, low penetration), beta particles (fast electrons, moderate penetration), gamma rays (electromagnetic, highly penetrating). The half-life is the time for half the nuclei to decay. Nuclear equations show the change: alpha decreases mass number by 4 and atomic number by 2. Radiation is measured with a Geiger‑Müller tube; background radiation must be subtracted.
放射性衰变：α 粒子（氦核，贯穿力弱）、β 粒子（快速电子，贯穿力中等）、γ 射线（电磁波，贯穿力强）。半衰期是半数原子核发生衰变所需的时间。核方程揭示了变化：α 衰变使质量数减 4，原子序数减 2。辐射用盖革‑米勒管测量；需扣除本底辐射。
current is the flow of charge; potential difference drives it; resistance opposes it. Ohm' uits share current. Power = I V = I² R. In magnetism, the motor effect (force on a current‑ th alternating current and change voltage according to the turns ratio: Vₚ / Vₛ = Nₚ / Nₛ.
在电学中，电流是电荷的流动；电势差推动电流；电阻阻碍电流。对于欧姆导体，欧姆定律 (V = I R) 成立。串联电路分压，并联电路分流。功率 = I V = I² R。在磁学中，电动机效应（电流在磁场中受力）和发电机效应（电磁感应）是核心原理。变压器仅在交流电下工作，并根据匝数比改变电压：Vₚ / Vₛ = Nₚ / Nₛ。
V = I R | P = I V | Vₚ / Vₛ = Nₚ / Nₛ
Published by TutorHao | WJEC Science Revision Series | aleveler.com
更多咨询请联系16621398022（同微信）
或截图后用「扫一扫 → 相册」选择本图