📚 Common Misconceptions in Year 7 CIE Science and How to Correct Them | Year 7 CIE 科学常见误区与纠正方法
As students embark on their Year 7 CIE Science course, they encounter many new ideas about the living world, materials, and forces. However, prior everyday experiences often create misunderstandings that can block true scientific thinking. Identifying and correcting these misconceptions early is crucial for building confidence and accuracy in science. This article explores ten widespread misconceptions across biology, chemistry and physics, and explains the correct scientific concepts in a clear, accessible way.
当学生开始CIE七年级科学课程时，他们会接触到许多关于生命世界、物质和力的新概念。然而，先前的日常经验常常造成误解，阻碍真正的科学思维。及早发现并纠正这些误区，对于建立科学自信和准确性至关重要。本文探讨了生物、化学和物理中十个普遍存在的误区，并以清晰易懂的方式解释正确的科学概念。
1. Plants Get Their Food from the Soil | 植物从土壤中获取食物
Many students believe that plants take in food from the soil through their roots, much like animals feed. They see fertiliser being added to soil and think it is the plant's main meal.
许多学生认为植物通过根部从土壤中吸收食物，就像动物进食一样。他们看到土壤中添加了肥料，便以为那是植物的主要食物。
In reality, plants make their own food through photosynthesis. Using sunlight, carbon dioxide from the air, and water from the soil, plants produce glucose (a sugar) and release oxygen. The roots do absorb water and dissolved minerals, but these are raw materials, not food. The food is manufactured in the leaves.
实际上，植物通过光合作用制造自己的食物。利用阳光、空气中的二氧化碳和土壤中的水，植物产生葡萄糖（一种糖）并释放氧气。根部确实吸收水和溶解的矿物质，但这些是原料，而不是食物。食物是在叶片中制造的。
carbon dioxide + water → glucose + oxygen
光合作用的单词方程：二氧化碳 + 水 → 葡萄糖 + 氧气
2. Substances Disappear When They Burn | 物质燃烧时消失了
When a log burns in a campfire, students often notice a pile of ash that is much lighter than the original log. This leads to the misconception that matter is destroyed during burning.
当木柴在篝火中燃烧时，学生常常注意到一堆灰烬比原来的木柴轻得多。这导致误解，认为物质在燃烧过程中被破坏了。
Burning is a chemical reaction with oxygen. The log turns into carbon dioxide, water vapour, and other gases that escape into the air, leaving behind the solid ash. If you could capture all the gases, their total mass together with the ash would equal the mass of the original log plus the oxygen used. This illustrates the law of conservation of mass.
燃烧是与氧气发生的化学反应。木柴转变成二氧化碳、水蒸气和其他气体，这些气体散逸到空气中，留下固体灰烬。如果能够收集所有气体，它们与灰烬的总质量将等于原来木柴加上所用氧气的质量。这体现了质量守恒定律。
magnesium + oxygen → magnesium oxide
例如：镁 + 氧气 → 氧化镁（质量不灭）
3. Heavier Objects Fall Faster | 重的物体下落更快
If you drop a hammer and a feather at the same time on Earth, the hammer hits the ground first. Many students conclude that heavier objects naturally fall faster than lighter ones.
如果在地球上同时丢下一把锤子和一根羽毛，锤子会先着地。许多学生便得出结论：重的物体天生比轻的物体下落更快。
In the absence of air resistance, all objects accelerate towards the Earth at the same rate (approximately 9.8 m/s²). On the Moon, where there is no air, a hammer and a feather fall side by side, as demonstrated by the Apollo 15 mission. On Earth, air resistance slows the feather down far more than the hammer, creating the false impression.
在没有空气阻力的情况下，所有物体都以相同的加速度（约9.8 m/s²）向地球下落。在月球上，没有空气，锤子和羽毛并排下落，正如阿波罗15号任务所展示的。在地球上，空气阻力对羽毛的减速作用远大于锤子，从而产生了错误的印象。
4. Breathing and Respiration Are the Same Thing | 呼吸就是呼吸作用
Students commonly use the word 'respiration' to mean the act of breathing in and out. They may think that respiration only happens in the lungs.
学生通常用“呼吸”一词来指吸气和呼气的动作。他们可能认为呼吸作用只发生在肺部。
Breathing (ventilation) is the physical movement of air into and out of the lungs. Respiration, however, is a chemical process that occurs in every living cell. During aerobic respiration, cells use oxygen to release energy from glucose, producing carbon dioxide and water as waste. This cellular process is what powers all life activities.
呼吸（通气）是空气进出肺部的物理运动。然而，呼吸作用（细胞呼吸）是发生在每个活细胞中的化学过程。在有氧呼吸中，细胞利用氧气从葡萄糖中释放能量，并产生二氧化碳和水作为废物。这一细胞过程为所有生命活动提供动力。
5. Melting Ice Is a Chemical Change | 冰融化是化学变化
Because ice looks very different from liquid water, some students classify melting as a chemical reaction where a new substance is formed.
由于冰与液态水看起来非常不同，一些学生将融化归类为形成新物质的化学反应。
Melting is a physical change. The particles in ice gain energy and move apart to become liquid water, but the chemical identity (H₂O) remains exactly the same. Freezing and melting are reversible without any new substance being produced. A chemical change, by contrast, creates substances with new chemical properties, like rusting.
融化是物理变化。冰中的粒子获得能量并移动到液态水状态，但化学本质（H₂O）完全相同。冻结和融化是可逆的，不会产生任何新物质。相反，化学变化会产生具有新化学性质的物质，例如生锈。
6. Electric Current Gets Used Up in a Circuit | 电流在电路中被用完
When a lamp is connected in a circuit, students often think that the electric current starts off large at the battery, decreases as it passes through the lamp, and returns to the battery much smaller.
当灯泡连接在电路中时，学生常认为电流从电池出发时很大，通过灯泡后变小，回到电池时变小了。
Electric current is the flow of charge. In a simple series circuit, the current is the same everywhere. The charges do not get used up; they simply transfer energy to the lamp, which converts it into light and heat. The battery provides the energy, but the charge carriers circulate continuously. Think of a bicycle chain: the links are not consumed; they just carry the force around.
电流是电荷的流动。在简单的串联电路中，各处电流相同。电荷不会被消耗；它们只是将能量传递给灯泡，灯泡将能量转化为光和热。电池提供能量，但电荷载流子持续循环。想象一下自行车链条：链节不会被消耗，它们只是传递力量。
7. All Microorganisms Are Harmful | 所有微生物都有害
Young learners often hear about germs causing diseases and conclude that bacteria, viruses, and fungi are universally bad and should be eliminated.
年幼的学习者经常听说病菌会致病，便得出结论：细菌、病毒和真菌普遍有害，应该消灭。
While some microorganisms cause illness, many are essential for life. Bacteria in our gut help digest food and produce vitamins. Yeast (a fungus) is used to make bread and biofuels. Decomposers recycle nutrients in ecosystems by breaking down dead matter. Without microbes, life on Earth would not function.
虽然有些微生物会致病，但许多对生命至关重要。肠道中的细菌帮助消化食物并产生维生素。酵母（一种真菌）用于制作面包和生物燃料。分解者通过分解死亡物质来回收生态系统中的养分。没有微生物，地球上的生命将无法运作。
8. Dissolving Means the Solute Disappears | 溶解意味着溶质消失了
When salt is stirred into water, it seems to vanish. Students may think the salt has been destroyed or has turned into water.
当盐被搅拌到水中时，似乎消失了。学生可能认为盐被破坏或变成了水。
Dissolving is a physical process where the solute particles separate and spread out evenly among the solvent particles. The salt is still present. If you evaporate the water, the salt will remain as a solid. The mass of the solution equals the mass of solvent plus solute, which can be demonstrated by careful measurement.
溶解是一个物理过程，溶质粒子分离并均匀分散在溶剂粒子之间。盐仍然存在。如果蒸发掉水，盐会以固体形式残留。溶液的质量等于溶剂加溶质的质量，这可以通过仔细的测量来证明。
9. The Sun Orbits the Earth | 太阳围绕地球转
Every day we see the Sun rise in the east, move across the sky, and set in the west. This visual experience leads many students to assume the Sun travels around a stationary Earth.
每天我们看见太阳从东方升起，划过天空，在西方落下。这种视觉体验让许多学生认为太阳围绕静止的地球转动。
In reality, the Earth rotates on its axis once every 24 hours, which creates the apparent motion of the Sun. The Earth, along with other planets, actually orbits the Sun in a heliocentric model. The apparent daily motion is due to our spinning planet, not the Sun moving around us.
实际上，地球每24小时绕轴自转一周，这造成了太阳的视运动。地球与其他行星一起，在以太阳为中心的日心模型中围绕太阳运行。这种每日视运动是由我们旋转的行星造成的，而不是太阳绕着我们转。
10. The Heart Is Part of the Respiratory System | 心脏是呼吸系统的一部分
Since the heart and lungs are located close together in the chest, and they work together to deliver oxygen to the body, students often mistakenly place the heart in the respiratory system.
由于心脏和肺在胸腔中位置接近，并且它们共同协作将氧气输送到全身，学生经常错误地将心脏归入呼吸系统。
The heart is the pump of the circulatory system, which transports oxygen, nutrients, and waste around the body through blood. The lungs belong to the respiratory system, handling gas exchange. While these systems interact closely, they are separate organ systems with distinct functions.
心脏是循环系统的泵，通过血液将氧气、营养物质和废物输送到全身。肺属于呼吸系统，负责气体交换。虽然这两个系统密切互动，但它们是功能不同的独立器官系统。
Published by TutorHao | CIE Science Revision Series | aleveler.com
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