📚 Common Misconceptions in Year 11 WJEC Science and How to Correct Them | Year 11 WJEC 科学常见误区与纠正方法
As students prepare for their WJEC Science GCSE, they often hold persistent misconceptions that can cost marks in exams. Understanding the correct scientific principles and the reasons behind these mistakes is crucial for Year 11 revision. This article identifies ten of the most common misunderstandings in Physics, Chemistry, and Biology, and provides clear explanations to set the record straight.
在备战 WJEC 科学 GCSE 时，学生往往存在一些顽固的误区，这些误区可能在考试中造成失分。掌握正确的科学原理并理解错误的原因对于 Year 11 复习至关重要。本文梳理了物理、化学和生物三科中最常见的十个误解，并给出清晰的解释来拨乱反正。
1. Physics: ‘A Constant Force Is Needed to Keep an Object Moving’ | 物理：’物体运动需要持续有力的作用’
Many students believe that if an object is moving, a resultant force must be acting on it in the direction of motion, and if the force stops, the object will stop immediately. This idea comes from everyday experience with friction, where moving objects slow down and stop.
许多学生认为，如果物体在运动，必然有一个沿运动方向的合力作用在它身上，一旦力消失，物体就会立刻停止。这种想法源自日常摩擦力的体验，运动物体都会减速停下。
The correct view, based on Newton’s First Law, is that an object will continue at a constant velocity (or remain at rest) unless a resultant force acts on it. Forces change the motion, not sustain it. In the absence of friction, a moving object does not need a forward force to keep going.
正确的观点基于牛顿第一定律：物体将保持匀速直线运动或静止状态，除非有合力作用于它。力改变运动状态，而不是维持运动。在无摩擦的情况下，运动物体不需要向前的力也能继续前进。
2. Physics: ‘Heavier Objects Fall Faster Than Lighter Ones’ | 物理：’重物比轻物下落更快’
It is a very common belief that if you drop a heavy ball and a light ball from the same height, the heavy one will hit the ground first. Students often cite gravity pulling harder on the heavier object.
一个极为常见的想法是，如果从同一高度释放一个重球和一个轻球，重的会先落地。学生往往认为重力对重物的拉扯更厉害。
In reality, when air resistance is negligible, all objects accelerate towards the Earth at the same rate (g ≈ 9.8 m/s²). Galileo’s thought experiments and the Apollo 15 hammer-feather drop demonstrated this. Mass does not affect the acceleration due to gravity; a greater mass also means a greater inertia, so the ratio is constant.
事实上，当空气阻力可以忽略时，所有物体都以相同的加速度 (g ≈ 9.8 m/s²) 落向地面。伽利略的思想实验和阿波罗 15 号的锤子-羽毛实验都证明了这一点。质量并不影响重力加速度；更大的质量也意味着更大的惯性，因此两者的比值恒定。
3. Physics: ‘Electric Current Gets Used Up in a Circuit’ | 物理：’电流在电路中被消耗’
Learners often imagine electric current as a substance that enters a component (like a bulb), does work, and emerges weaker. This leads to the prediction that the current before a bulb is larger than the current after it.
学习者常把电流想象成一种物质，它进入元件（如灯泡）后做功，出来时变弱了。这会导致他们预测灯泡之前的电流大于之后的电流。
Current is the rate of flow of charge. In a series circuit, charge is conserved, so the current is exactly the same at every point. It is energy that is transferred, not current that is consumed. A bulb lights because electrical energy is converted into heat and light, not because electrons are used up.
电流是电荷流动的速率。在串联电路中，电荷守恒，因此各处的电流完全相同。被消耗的是能量，而不是电流本身。灯泡发光是因为电能转化为热和光，而不是因为电子被用掉了。
4. Chemistry: ‘Bonds Store Energy, and Breaking Them Releases It’ | 化学：’化学键储存能量，断裂时会释放能量’
In everyday language, we say food and fuels ‘contain’ energy. Students then transfer this idea to chemical bonds, assuming that breaking bonds releases the stored energy, much like snapping a stretched rubber band.
在日常生活中，我们说食物和燃料’含有’能量。学生便将这种想法迁移到化学键上，认为断裂化学键会释放储存的能量，就像拉断一根拉伸的橡皮筋。
In chemistry, energy must be supplied to break bonds (endothermic process), and energy is released when new bonds form (exothermic process). In an exothermic reaction, the energy released by forming new bonds exceeds the energy absorbed to break the original bonds. The bonds themselves do not store energy like a spring.
化学上，断裂化学键需要供给能量（吸热过程），而形成新化学键则会释放能量（放热过程）。在放热反应中，形成新键释放的能量大于断裂旧键吸收的能量。化学键本身并不像弹簧一样储存能量。
5. Chemistry: ‘Ionic Compounds Can Conduct Electricity Only When Molten’ | 化学：’离子化合物只能在熔融状态下导电’
A frequent exam mistake is to state that ionic compounds conduct only when they are melted, ignoring the behaviour of aqueous solutions. Students may imagine that dissolving destroys the ions.
一个常见的考试错误是说离子化合物只在熔融时导电，而忽略了其水溶液的行为。学生可能认为溶解会破坏离子。
Ionic compounds conduct electricity when their ions are free to move. This happens when the substance is molten (liquid state) or dissolved in water. In an aqueous solution, water molecules separate the ions from the lattice, leaving them mobile and able to carry charge. Solid ionic compounds do not conduct because the ions are held in fixed positions.
离子化合物之所以导电，是因为离子可以自由移动。这在物质熔融（液态）或溶于水时都会发生。在水溶液中，水分子将离子从晶格中分离出来，使其自由移动并携带电荷。固态离子化合物不导电，因为离子被固定在特定位置上。
6. Chemistry: ‘Mass Is Lost or Gained During a Chemical Reaction’ | 化学：’化学反应中质量会变化’
Observing a candle burning away or rust appearing to add weight leads many to think that mass is not conserved. Students often believe that gases do not have mass, so they ignore them.
观察到蜡烛燃烧后消失，或者铁生锈后似乎变重，让许多人认为质量不守恒。学生常认为气体没有质量，因此忽略它们。
The law of conservation of mass states that in a chemical reaction, the total mass of reactants equals the total mass of products. Apparent mass changes occur because a gas is either entering the system (e.g., oxygen during rusting) or leaving it (e.g., carbon dioxide and water vapour from a burning candle). Including all substances, the mass stays constant.
质量守恒定律指出，在化学反应中，反应物的总质量等于生成物的总质量。表观质量变化是因为有气体进入系统（如铁锈生成时的氧气）或离开系统（如蜡烛燃烧生成的二氧化碳和水蒸气）。如果纳入所有物质，质量保持不变。
7. Biology: ‘Plants Photosynthesise During the Day and Respire Only at Night’ | 生物：’植物白天进行光合作用，只在晚上进行呼吸作用’
Many learners think that respiration is the opposite of photosynthesis and that plants cannot do both at the same time. They therefore assume respiration only happens in the dark.
许多学习者认为呼吸作用是光合作用的逆过程，植物无法同时进行两者。因此他们推断呼吸作用只在黑暗中进行。
Respiration is an ongoing process that occurs in all living cells, all the time, to release energy for life processes. During daylight, plants carry out both photosynthesis (which produces glucose and oxygen) and respiration (which uses glucose and oxygen). At night, when photosynthesis stops, respiration continues.
呼吸作用是一个持续的过程，所有活细胞每时每刻都在进行，为生命活动释放能量。在白天，植物同时进行光合作用（产生葡萄糖和氧气）和呼吸作用（消耗葡萄糖和氧气）。到了晚上，光合作用停止，但呼吸作用仍在继续。
8. Biology: ‘Organisms Evolve Traits Because They Need Them to Survive’ | 生物：’生物进化出特征是因为它们需要这些特征来生存’
Students often describe evolution as a purposeful process, for example, ‘giraffes grew longer necks because they needed to reach high leaves.’ This reflects a Lamarckian view rather than Darwinian natural selection.
学生常常把进化描述为一个有目的的过程，例如’长颈鹿因为需要够到高处的树叶，所以脖子就变长了’。这反映的是拉马克式的观点，而不是达尔文的自然选择。
Evolution by natural selection is not goal-directed. Variation already exists within a population due to random mutations. Those individuals with traits better suited to the environment are more likely to survive and reproduce, passing on their alleles. Longer-necked giraffes did not arise because of a ‘need’; they had a selective advantage over shorter-necked individuals.
自然选择驱动的进化并非有目标的。种群内因随机突变本来就存在变异。那些拥有更适应环境特征的个体更有可能存活并繁殖，从而将等位基因传递下去。长颈鹿的长脖子不是因为’需要’而出现的；只是长脖子个体比短脖子个体具有选择优势。
9. Biology: ‘Dominant Alleles Are More Common in a Population’ | 生物：’显性等位基因在种群中更常见’
A widespread misunderstanding is that if an allele is dominant, it must be frequent in the gene pool. Students often equate dominance with numerical majority.
一个普遍的误解是：如果一个等位基因是显性的，它在基因库中的频率就一定高。学生常常把显性与数量上的多数等同起来。
Dominant and recessive refer to the phenotype expressed in a heterozygote, not to allele frequency. There are many examples where a dominant allele is rare (e.g., polydactyly is caused by a dominant allele but occurs in very few people) and where a recessive allele is very common (e.g., the allele for O blood type). Frequency is determined by the selective pressures and genetic drift, not by dominance.
显性和隐性是指杂合子中表达的表现型，与等位基因频率无关。有许多例子表明显性等位基因很罕见（如多指症由显性等位基因引起，但患者极少），而隐性等位基因却非常普遍（如 O 型血等位基因）。频率由选择压力和遗传漂变决定，而非显隐性本身。
10. General Science: ‘Energy Is Used Up and Disappears’ | 综合科学：’能量被用掉并消失了’
In everyday language, we talk about ‘using up’ electricity or ‘losing’ energy. Many students therefore believe that energy is consumed and vanishes after doing work, rather than being conserved.
在日常用语中，我们会说’用光’了电，或者能量’流失’了。因此许多学生相信能量在做功后就被消耗并消失了，而不是被保存下来。
The principle of conservation of energy is fundamental: energy cannot be created or destroyed, only transferred or converted from one form to another. When a kettle boils, electrical energy is transferred into the thermal energy of the water and surroundings. The energy still exists but has been spread out (dissipated) and is less useful. Nothing disappears.
能量守恒原理是根本的：能量既不能被创造也不能被消灭，只能从一种形式转化为另一种形式，或从一个物体转移到另一个物体。当水壶烧水时，电能转化为水和周围环境的热能。能量依然存在，只是散逸（耗散）了，变得不那么有用。没有任何东西消失了。
Published by TutorHao | Science Revision Series | aleveler.com
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