📚 KS3 CIE Word Equations | KS3 CIE 文字方程式
At KS3, you meet chemical reactions in the lab and in everyday life. A word equation is a clear, simple way to record the names of the substances that react and the substances that are made. It is often the first kind of equation you write before moving on to chemical formulae.
在 KS3 阶段，你会在实验室和日常生活中遇到化学反应。文字方程式是一种清晰、简单的方法，用来记录参加反应的物质名称和生成的物质名称。它通常是你学习化学式之前最先书写的一种方程式。
1. What is a Word Equation? | 什么是文字方程式？
mple, when carbon burns in oxygen, the word equation is: carbon + oxygen → carbon dioxide.
文字方程式使用化学物质的完整名称来描述反应。它不使用 Mg、O 或 CO₂ 等符号。例如，碳在氧气中燃烧时，文字方程式为：碳 + 氧气 → 二氧化碳。
This type of equation tells you what happens but not how much of each substance is needed. That is why word equations are useful for younger students: they focus on the names and the direction of change.
这种方程式告诉你发生了什么，但不告诉你每种物质需要多少。这就是为什么文字方程式对低年级学生很有用：它专注于名称和变化的方向。
2. Reactants and Products | 反应物与生成物
Reactants are the starting substances. They are always written on the left-hand side of the arrow. Products are the new substances formed by the reaction. They are always written on the right-hand side of the arrow.
反应物是起始物质。它们总是写在箭头的左侧。生成物是反应生成的新物质。它们总是写在箭头的右侧。
ulfur → zinc sulfide. Zinc and sulfur are the reactants. Zinc sulfide is the only product.
例如，在锌和硫的反应中：锌 + 硫 → 硫化锌。锌和硫是反应物。硫化锌是唯一的生成物。
3. The Arrow and Plus Signs | 箭头与加号
The arrow in a word equation means 'reacts to form' or 'produces'. The plus sign is used to separate different reactants or different products. It does not mean ordinary addition.
文字方程式中的箭头表示 '反应生成' 或 '产生'。加号用来分隔不同的反应物或不同的生成物。它并不表示普通的加法。
A simple formation reaction can be written like this:
一个简单的化合反应可以写成这样：
magnesium + oxygen → magnesium oxide
This reads as: magnesium reacts with oxygen to form magnesium oxide.
这读作：镁与氧气反应生成氧化镁。
4. Writing Word Equations from Observations | 根据现象书写文字方程式
In experiments, you often observe a colour change, a gas being produced, a temperature change, or a precipitate forming. These observations help you identify the reactants and products.
在实验中，你常常观察到颜色变化、有气体产生、温度变化或生成沉淀。这些现象帮助你识别反应物和生成物。
nd the ash is magnesium oxide. The word equation is: magnesium + oxygen → magnesium oxide.
如果一根灰色金属条燃烧时发出明亮的白色火焰并留下白色灰烬，这种金属很可能是镁，灰烬是氧化镁。文字方程式为：镁 + 氧气 → 氧化镁。
Another example: a green powder turns black when heated and gives off a gas that turns limewater cloudy. The green powder is copper carbonate, the black solid is copper oxide, and the gas is carbon dioxide.
另一个例子：一种绿色粉末加热后变黑，并放出使石灰水变浑浊的气体。绿色粉末是碳酸铜，黑色固体是氧化铜，气体是二氧化碳。
The word equation is: copper carbonate → copper oxide + carbon dioxide.
文字方程式为：碳酸铜 → 氧化铜 + 二氧化碳。
5. Common Word Equations: Combustion | 常见文字方程式：燃烧
Combustion means
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