Year 12 WJEC Science: Common Misconceptions and How to Correct Them | Year 12 WJEC 科学：常见误区与纠正方法

📚 Year 12 WJEC Science: Common Misconceptions and How to Correct Them | Year 12 WJEC 科学：常见误区与纠正方法

Moving from GCSE to Year 12 Science under the WJEC specification brings not just harder content, but also the need to unlearn oversimplifications. Many students hold misconceptions that seem logical but conflict with the deeper models required at AS level. This article identifies ten common errors in physics, chemistry and biology, explains the correct understanding, and shows how to avoid slipping back into old mental shortcuts.

从 GCSE 升入 WJEC Year 12 科学课程，难度增加的同时，还需要摒弃一些过度简化的认知。许多学生持有的误解看似合理，却与 AS 阶段要求的深层模型相冲突。本文列举物理、化学和生物中的十个常见误区，阐释正确理解，并说明如何避免重蹈旧的思维捷径。

1. Heavier Objects Always Fall Faster | 重物总是下落得更快

Many students recall Galileo’s thought experiment but still intuitively believe a bowling ball falls faster than a marble. In the absence of air resistance, all objects near Earth’s surface accelerate at 9.81 m s⁻² regardless of mass. The misconception arises because everyday experience includes air drag, which affects light objects with large surface areas more noticeably. For WJEC Unit 1 motion questions, always assume free fall unless air resistance is explicitly mentioned.

许多学生记得伽利略的思想实验，但仍直觉地认为保龄球比弹珠下落得快。在没有空气阻力的情况下，地球表面附近的所有物体都以 9.81 m s⁻² 加速，与质量无关。这种误解源于日常经验中包含了空气阻力，而空气阻力对质量轻、表面积大的物体影响更明显。在 WJEC 第一单元的运动问题中，除非明确说明存在空气阻力，否则应假定为自由落体。

2. Equilibrium Means Equal Concentrations | 平衡意味着浓度相等

Dynamic equilibrium in reversible reactions is often confused with a 50:50 mixture. In reality, equilibrium occurs when the rates of the forward and backward reactions become equal, not the concentrations of reactants and products. The position of equilibrium (yield) can heavily favour one side. WJEC Unit 2 frequently asks students to predict shifts using Le Chatelier’s principle, which applies to rate equality, not concentration equality.

可逆反应的动态平衡常被误解为 50:50 的混合物。实际上，平衡是指正反应和逆反应的速率相等，而不是反应物和产物的浓度相等。平衡位置（即产率）可以极大地偏袒某一方。WJEC 第二单元常要求学生运用勒夏特列原理预测平衡移动，该原理适用于速率相等，而非浓度相等。

3. Respiration Is Simply Breathing | 呼吸作用就是呼吸

In biology, ‘respiration’ refers to the biochemical process that releases energy from organic molecules in cells. Breathing (ventilation) is the mechanical movement of air into and out of the lungs. WJEC Unit 2 expects students to distinguish clearly between gas exchange and cellular respiration, including aerobic and anaerobic pathways. Saying ‘respiration is breathing’ will lose marks in exam explanations of energy release.

在生物学中，“呼吸作用”指从细胞内的有机分子中释放能量的生化过程。呼吸（通气）则是空气进出肺部的机械运动。WJEC 第二单元要求学生明确区分气体交换和细胞呼吸，包括有氧和无氧途径。在考试中若解释能量释放时说“呼吸作用就是呼吸”，将导致失分。

4. Atoms Cannot Be Divided | 原子不可分割

The Greek origin ‘atomos’ means indivisible, which is a historical relic. AS Chemistry under WJEC Unit 1 reveals that atoms consist of protons, neutrons and electrons, and the nucleus itself can undergo radioactive decay or fission. The key is that an atom is the smallest particle of an element that retains chemical properties; it is divisible physically but not chemically in ordinary reactions. Confusing chemical indivisibility with absolute indivisibility is a frequent stumbling block.

希腊词根“atomos”意为不可分割，这已是历史遗迹。WJEC 第一单元的 AS 化学揭示原子由质子、中子和电子组成，并且原子核本身可发生放射性衰变或裂变。关键在于原子是保持元素化学性质的最小粒子；它在普通化学反应中化学上不可分割，但物理上可以分割。混淆化学不可分性与绝对不可分性是一个常见绊脚石。

5. Energy Gets ‘Used Up’ | 能量被“用完”

Energy is never created or destroyed, only transferred or transformed. When a fuel burns, chemical potential energy is transferred to thermal energy of the surroundings; the total energy remains constant. WJEC Physics Unit 1 emphasises the principle of conservation of energy. Students may say a battery ‘runs out of energy’, but the energy has merely been dispersed as heat and work, becoming less available.

能量既不会凭空产生，也不会凭空消失，只会传递或转化。当燃料燃烧时，化学势能转化为周围环境的热能；总能量保持不变。WJEC 物理第一单元强调能量守恒原理。学生可能会说电池“没电了”，但能量只是以热和功的形式耗散，变得不再可用。

6. Current Gets Used Up in a Circuit | 电流在电路中被消耗

A widespread misconception is that electric current diminishes as it passes through components like bulbs. In a series circuit, current is the same at all points because charge is conserved. What changes is the energy carried, not the flow rate of charge. WJEC Unit 2 circuit analysis relies on applying Kirchhoff’s first law correctly. Using the rope-loop model or the ‘jam sandwich’ model can help rewire this thinking.

一个普遍的误解是电流在经过灯泡等元件后会减小。在串联电路中，由于电荷守恒，各点的电流都相同。变化的是所携带的能量，而不是电荷的流动速率。WJEC 第二单元的电路分析依赖于正确运用基尔霍夫第一定律。使用绳圈模型或“果酱三明治”模型有助于纠正这种思维。

7. Plants Get Their Food from the Soil | 植物从土壤中获取食物

Students often believe plants absorb ‘food’ through their roots. In reality, plants make their own organic molecules via photosynthesis using carbon dioxide and water. Minerals taken up from the soil are nutrients, not energy sources. WJEC Unit 2 questions on photosynthesis explicitly require stating that glucose production depends on light energy, not soil organic matter. This misconception stems from the everyday use of the word ‘plant food’.

学生常认为植物通过根部吸收“食物”。实际上，植物利用二氧化碳和水通过光合作用自己制造有机分子。从土壤中吸收的矿物质是营养物质，而非能量来源。WJEC 第二单元关于光合作用的题目明确要求说明葡萄糖的产生依赖于光能，而非土壤中的有机物。这一误解源于日常用语“植物养料”。

8. Chemical Bonds Store Energy | 化学键储存能量

It is common to hear that ‘energy is stored in chemical bonds’, but bond breaking requires an input of energy (endothermic) and bond forming releases energy (exothermic). The net energy change in a reaction comes from the difference between the energy needed to break bonds and the energy released when new bonds form. WJEC Unit 1 energetics calculations clearly treat bond breaking as positive ΔH. Misusing the storage metaphor leads to sign errors in Hess’s law problems.

常听说“能量储存在化学键中”，但断裂化学键需要摄入能量（吸热），形成化学键则释放能量（放热）。反应中的净能量变化来自于断键所需能量与成键所释放能量之间的差值。WJEC 第一单元能量学计算明确将断键视为正的 ΔH。误用储存隐喻会导致盖斯定律问题中出现符号错误。

9. Heat and Temperature Are the Same Thing | 温度和热量是一回事

Temperature measures the average kinetic energy of particles, while heat is the transfer of thermal energy between objects at different temperatures. An object can have a high temperature but contain little heat if it is small. WJEC Physics Unit 1 includes specific heat capacity and latent heat, where this distinction is crucial. The misconception leads students to confuse why a sparkler at 1000 °C does not burn you as severely as a boiling kettle.

温度测量粒子平均动能，而热量是处于不同温度的物体之间传递的热能。一个物体温度可以很高，但如果体积很小，所含热量却不多。WJEC 物理第一单元涉及比热容和潜热，这一区分至关重要。这一误解导致学生困惑为什么 1000 °C 的烟花棒不会像烧开的水壶那样严重烫伤你。

10. Natural Selection Means Individuals Adapt | 自然选择是指个体适应

A classic biological error is to believe that individual organisms can evolve or adapt during their lifetime in response to environmental pressure. Natural selection acts on variation already present in a population; individuals with advantageous alleles are more likely to survive and reproduce, shifting allele frequencies over generations. WJEC Unit 2 requires explaining that adaptation is a population-level process, not an individual one, as famously misstated by Lamarck.

一个经典的生物学错误是认为生物个体可以在其一生中根据环境压力进化或适应。自然选择作用于种群中已经存在的变异；携带有利等位基因的个体更有可能生存和繁殖，从而使等位基因频率在世代间发生改变。WJEC 第二单元要求解释适应是一个种群层面的过程，而非个体过程，这正是拉马克的著名错误表述。

Published by TutorHao | WJEC Science Revision Series | aleveler.com

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