IB Science: Last-Minute Revision Guide | IB 科学：考前冲刺笔记

📚 IB Science: Last-Minute Revision Guide | IB 科学：考前冲刺笔记

With the IB science exams approaching, focused revision can make the difference between an average score and a top grade. This guide condenses essential strategies for Biology, Chemistry and Physics, covering command words, data analysis, experimental skills, common equations and IA reminders. The aim is not to replace deep learning but to sharpen your approach, helping you navigate Papers 1, 2 and 3 with confidence.

随着 IB 科学考试临近，有针对性的复习可能是普通分数与高分之间的关键。这份指南浓缩了生物、化学和物理的核心策略，涵盖指令词、数据分析、实验技能、常见方程式以及内部评估（IA）提醒。目的不是取代深度学习，而是优化你的应试方法，帮助你从容应对试卷一、二和三。

1. Conceptual Command Words | 理解指令词

IB exam questions rely heavily on command terms such as ‘state’, ‘describe’, ‘explain’, ‘discuss’ and ‘evaluate’. Recognising what each term demands is essential for structuring your answers and avoiding unnecessary detail or omissions. For example, ‘state’ requires a concise answer without reasoning, while ‘explain’ needs a scientific mechanism or cause-and-effect relationship.

IB 考试题目高度依赖指令词，如“陈述”、“描述”、“解释”、“讨论”和“评价”。识别每个术语的要求对于组织答案、避免多余细节或遗漏至关重要。例如，“陈述”只需给出简洁答案而无需解释，而“解释”则需要提供科学机制或因果关系。

State – Give a specific name, value or brief phrase; no justification needed. / 给出具体名称、数值或简短短语，无需理由。
Describe – Provide a detailed account of characteristics, trends or observations. / 详细说明特征、趋势或观察结果。
Explain – Give reasons, mechanisms or relationships, often linking cause and effect. / 给出原因、机制或关系，通常要关联因果。
Discuss – Present arguments for and against, consider limitations and offer a balanced conclusion. / 提出赞成与反对的论点，考虑局限性，并给出平衡的结论。
Evaluate – Examine strengths and weaknesses, then make a judgement supported by evidence. / 分析优缺点，然后基于证据做出判断。

Practise identifying command words in past papers and highlight them; this small habit prevents misreading and saves marks. In Data-Based questions, ‘suggest’ often invites hypotheses or inferences from given data, not mere repetition. / 练习在历年真题中标出指令词；这个小习惯能防止误读，保住分数。在数据题中，“建议”通常要求根据所给数据提出假设或推断，而非简单重复数据。

2. Key Terminology and Definitions | 核心术语与定义

Precision with scientific vocabulary is a hallmark of high-scoring scripts. Ambiguous phrasing like ‘energy is lost’ instead of ‘energy is dissipated as heat to the surroundings’ can lose marks. Review the definitions in your subject guide for topics such as bonding, energetics, homeostasis and fields.

科学词汇的精确性是高分答卷的标志。模糊的表述如“能量损失了”而不是“能量以热的形式散失到周围环境中”会丢分。复习学科指南中关于化学键、能量学、稳态和场等主题的定义。

Subject	Common Terms (English)	常见术语（中文）
Biology	Homeostasis, osmosis, alleles, trophic level, transpiration	稳态、渗透、等位基因、营养级、蒸腾作用
Chemistry	Enthalpy, entropy, electronegativity, activation energy, ligand	焓、熵、电负性、活化能、配体
Physics	Momentum, potential difference, emf, diffraction, half-life	动量、电势差、电动势、衍射、半衰期

When revising definitions, use flashcards with the term on one side and the exact IB definition plus an example on the other. Avoid loose language; for instance, say ‘the net movement of water molecules from a region of higher water potential to a region of lower water potential through a partially permeable membrane’ rather than ‘water moving through a membrane’. / 复习定义时，使用一面是术语、另一面是准确的 IB 定义加例子的闪卡。避免不严谨的语言；例如，应该说“水分子通过部分透性膜从水势较高区域净移动到水势较低区域”，而不是“水穿过膜”。

3. Mastering Data-Based Questions | 掌握数据题

Data-based questions appear in Paper 2 and especially Paper 3 Section A. They test your ability to interpret graphs, tables and charts, calculate slopes, draw conclusions and evaluate limitations. First, read the axes and units carefully; many students lose marks by overlooking logarithmic scales or standard form.

数据题出现在试卷二，尤其是试卷三 A 部分。它们考查你解读图形、表格和图表，计算斜率、得出结论并评价局限性的能力。首先，仔细阅读坐标轴和单位；许多学生因忽略对数刻度或科学记数法而丢分。

When asked to describe a trend, mention the relationship (positive, negative, plateau), use data values and quote the ranges. For a calculation of gradient, use the formula:

gradient = Δy / Δx

and show the triangle on the graph. Always include correct units and significant figures. / 当要求描述趋势时，要说明关系（正相关、负相关、平台期），引用数据值和范围。计算斜率时使用公式：

斜率 = Δy / Δx

并在图上画出三角形。始终注明正确单位和有效数字。

For evaluation, discuss systematic errors, random uncertainties, sample size and whether the data support the hypothesis. Use phrases like ‘the data suggest that… however, the small sample size limits the reliability of the conclusion’. / 评价时，讨论系统误差、随机不确定性、样本量以及数据是否支持假设。使用“数据表明……但样本量小限制了结论的可靠性”这类表述。

4. Exam Technique: Structured and Extended Response | 考试技巧：结构化与扩展作答

Long-answer questions in Section B of Paper 2 demand organised paragraphs with clear scientific reasoning. Start by identifying the key concept, then build a logical sequence: define, explain, give an example and link to the application. Using diagrams, where appropriate, can convey complex ideas efficiently.

试卷二 B 部分的长答题需要有组织的段落和清晰的科学推理。从识别关键概念开始，然后构建逻辑链条：定义、解释、举例并联系应用。适当时使用图表可以高效传达复杂概念。

Keep the ‘PEEL’ structure in mind: Point, Evidence, Explanation, Link back to the question. For instance, in a physics question about energy conservation, state the principle, cite the formula Eₖ = ½mv², show calculations and then link to the energy lost to friction. Avoid bullet points unless the question specifically allows them, because continuous prose often scores higher in ‘communication’. / 牢记“PEEL”结构：论点、证据、解释、回扣问题。例如在能量守恒的物理题中，陈述原理，引用公式

Eₖ = ½mv²

，展示计算过程，然后联系摩擦损失的能量。除非题目明确允许，避免使用项目符号，因为连贯的散文常在“交流”分上得分更高。

5. Mathematical Essentials and Common Equations | 数学基础与常见方程

All IB science papers assume competence in basic mathematics. You must be comfortable with unit conversions, standard form, ratios, percentage uncertainty and rearranging equations. Especially in Chemistry and Physics, memorising key formulae saves critical time.

所有 IB 科学试卷都要求具备基础数学能力。你必须熟练掌握单位换算、科学记数法、比例、百分比不确定度和方程变形。尤其在化学和物理中，熟记关键公式可以节省宝贵时间。

Some high-frequency equations include:

物理/Physics:

F = ma, V = IR, P = IV, E = mcΔθ, a = v²/r

化学/Chemistry:

n = m/M, PV = nRT, pH = -log[H⁺], ΔG = ΔH – TΔS

生物/Biology:

Magnification = image size ÷ actual size, Chi-squared test χ² = Σ((O – E)² / E)

Always check that your numerical answer makes physical sense; a negative activation energy or a temperature below absolute zero indicates a calculation error. Show your working clearly, because even with a wrong final answer you can earn method marks. / 始终检查你的数值答案是否合理；负的活化能或低于绝对零度的温度说明计算有误。清晰展示解题步骤，因为即使最终答案错了也能获得方法分。

6. Experimental Design and Error Analysis | 实验设计与误差分析

Questions on experimental design appear frequently in Paper 2 and the Section A practical data analysis. You must be able to identify independent, dependent and controlled variables, suggest improvements and evaluate uncertainties. Precision is vital: ‘repeat the experiment’ alone is insufficient; say ‘repeat the measurement three times and calculate a mean to reduce random error’.

实验设计题频繁出现在试卷二和试卷三 A 部分的实际数据分析中。你必须能够识别自变量、因变量和控制变量，提出改进建议并评价不确定性。准确性至关重要：只说“重复实验”是不够的；要说“重复测量三次并计算平均值以减少随机误差”。

When discussing errors, distinguish between systematic errors (e.g., a miscalibrated pH meter) and random errors (e.g., reaction time when using a stopwatch). Use terminology like ‘parallax error’ and ‘zero error’ appropriately. A well-structured response also mentions how to minimise each error: for parallax, read the meniscus at eye level; for zero error, subtract the zero reading. / 讨论误差时，要区分系统误差（如未校准的 pH 计）和随机误差（如使用秒表时的反应时间）。恰当使用“视差误差”、“零误差”等术语。结构良好的答案还会提及如何减少每种误差：对于视差，视线与弯月面水平；对于零误差，扣除零点读数。

7. IA (Internal Assessment) Last-Minute Checklist | IA 考前核对清单

Even in the final revision phase, a quick IA review can boost your confidence, as IA criteria overlap with exam skills. Check that your research question is focused and includes both independent and dependent variables. Verify your raw data table has clear headings with units and uncertainties, and that your processed data includes sample calculations.

即使在最后冲刺阶段，快速回顾 IA 也能增强信心，因为 IA 标准与考试技能有重叠。检查你的研究问题是否聚焦且包含自变量和因变量。确认原始数据表有清晰的标题，注明单位和不确定度，处理后的数据包含样本计算。

Does your graph have error bars, a line of best fit, and a meaningful title? / 你的图表是否有误差棒、最佳拟合线和有意义的标题？
Have you correctly propagated uncertainties for compound quantities such as density or rate? / 对于密度或速率等复合量，你是否正确传递了不确定度？
Is your conclusion fully supported by the data, and does it compare with accepted literature values where relevant? / 结论是否完全由数据支撑，是否在相关时与公认文献值进行了比较？

Revisit the IA mark scheme to ensure you are not missing easy marks in communication or personal engagement. A well-presented IA can also reinforce your understanding of experimental terminology for the written papers. / 重新审视 IA 评分标准，确保你不会在交流或个人参与方面丢分。一份精心完成的 IA 也能强化你对书面试卷中实验术语的理解。

8. Interdisciplinary Links: Environmental and Ethical Issues | 跨学科关联：环境与伦理议题

IB science syllabi embed environmental, ethical and socio-economic dimensions. Questions might ask you to discuss the implications of nuclear power, genetic modification or plastic waste. Preparing a few case studies will help you write balanced ‘discuss’ answers in any of the sciences.

IB 科学大纲融入了环境、伦理和社会经济维度。问题可能会要求你讨论核能、基因改造或塑料废弃物的影响。准备几个案例研究将帮助你在任何科学科目中写出平衡的“讨论”型答案。

For example, a biology question on IVF could lead to a discussion on embryo screening and ethical concerns. In chemistry, the Haber process links to food production and environmental nitrogen overload. Physics topics like radioactive waste disposal require weighing the benefits of nuclear medicine against long-term storage hazards. Use specific scientific vocabulary and reference real-world data where possible. / 例如，一道关于体外受精的生物题可能引出对胚胎筛选和伦理关切的讨论。在化学中，哈伯法联系到粮食生产和环境氮超载。放射性废物处置等物理话题需要权衡核医学的益处与长期储存危害。使用具体的科学词汇并尽可能引用真实世界数据。

9. Final Day Strategy and Exam Room Tips | 考试当天策略与考场贴士

On the day before the exam, shift from intense learning to strategic consolidation. Review your formula sheet, command word list and one-page summaries. Get a full night’s sleep; cognitive performance decreases significantly with fatigue. In the exam room, allocate time proportionally to the marks: for a 40-mark Paper 2, aim for roughly 1 minute per mark.

考试前一天，从高强度学习转向策略性巩固。复习公式表、指令词清单和一页纸摘要。保证充足睡眠；疲劳会显著降低认知表现。在考场，按分数比例分配时间：对于40分的试卷二，大约每题1分钟。

Attempt the questions you are most confident about first to build momentum, but mark the unanswered ones clearly. When stuck, write down related definitions or formulae; this often triggers retrieval. For multiple choice (Paper 1), eliminate clearly wrong options immediately to improve your odds. After finishing, if time remains, check your answers for unit errors and significant figures. / 先做最有把握的题目以建立节奏，但要清楚标记未答的题目。遇到卡壳时，写下相关的定义或公式，这常常能启动回忆。对于选择题（试卷一），立即排除明显错误的选项以提高正确率。完成后如还有时间，检查答案中的单位误差和有效数字。

Bring a transparent pencil case, two calculators (with fresh batteries), a ruler and a protractor. Remember that the IB permits unannotated copies of the data booklet; familiarise yourself with its layout so you can locate constants and equations swiftly. / 带上透明铅笔盒、两台计算器（带新电池）、尺子和量角器。记住 IB 允许携带未经标注的数据手册；熟悉它的编排，以便快速找到常数和公式。

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IB Science: Last-Minute Revision Guide | IB 科学：考前冲刺笔记