📚 Year 9 OCR Chemistry: Quick-Reference Terminology Guide | Year 9 OCR 化学：词汇术语速记指南
Mastering the language of chemistry is half the battle in Year 9. This guide collects the most important OCR Key Stage 3 terms you will encounter, organised into logical groups for quick revision. Use it alongside your practical work and end-of-topic tests to build a solid vocabulary foundation that will carry you all the way to GCSE.
掌握化学的语言是9年级成功的一半。这份指南汇总了你将遇到的最重要的 OCR 关键阶段3术语，并按照逻辑分组编排，便于快速复习。与你的实验和单元测试配合使用，奠定扎实的词汇基础，这将对你的整个 GCSE 阶段都有帮助。
1. Atoms, Elements and the Periodic Table | 原子、元素与周期表
An atom is the smallest unit of matter that can take part in a chemical reaction. It consists of a nucleus containing protons and neutrons, surrounded by electrons in energy levels.
原子是能参与化学反应的最小物质单元。它由一个包含质子和中子的原子核以及分布在能级中的电子构成。
An element is a pure substance made up of only one type of atom. All known elements are listed in the periodic table, where each element is represented by a unique chemical symbol, such as O for oxygen and Na for sodium.
元素是由同一种原子组成的纯净物。所有已知元素都列在周期表中，每种元素用一个独特的化学符号表示，如氧用 O，钠用 Na。
The atomic number (proton number) tells you how many protons are in the nucleus of an atom. In a neutral atom, the number of electrons equals the number of protons.
原子序数（质子数）表明原子核中有多少个质子。在中性原子中，电子数等于质子数。
The mass number is the total number of protons and neutrons in an atom’s nucleus. To find the number of neutrons, subtract the atomic number from the mass number.
质量数是原子核中质子与中子的总数。要计算中子数，用质量数减去原子序数。
The periodic table is arranged in order of increasing atomic number. Vertical columns are called groups; elements in the same group have similar chemical properties because they have the same number of electrons in their outer shell.
周期表按原子序数递增的顺序排列。竖列称为族；同一族的元素化学性质相似，因为它们最外层电子数相同。
Horizontal rows are called periods. As you move across a period, the atomic number increases and the properties of the elements change gradually from metallic to non-metallic.
横排称为周期。当你沿着一个周期从左到右移动时，原子序数增加，元素的性质从金属性逐渐变为非金属性。
2. Compounds, Molecules and Chemical Formulae | 化合物、分子与化学式
A compound is a substance formed when two or more different elements are chemically bonded together. A compound has properties very different from the elements that make it up.
化合物是两种或多种不同元素通过化学键结合形成的物质。化合物的性质与构成它的元素截然不同。
A molecule is a particle made up of two or more atoms strongly bonded together. Molecules can be elements (like O₂) or compounds (like H₂O).
分子是由两个或多个原子通过强键结合而成的粒子。分子可以是单质（如 O₂），也可以是化合物（如 H₂O）。
The chemical formula shows the symbols of the elements present and the ratio of atoms in the compound. In CO₂, for example, one carbon atom is bonded to two oxygen atoms.
化学式显示了化合物中所含元素的符号以及原子个数比。例如，在 CO₂ 中，一个碳原子与两个氧原子结合。
To name simple compounds, the metal always comes first, followed by the non-metal with its name ending in ‘-ide’. For instance, sodium and chlorine form sodium chloride.
在给简单化合物命名时，金属总是写在前面，非金属随后且词尾为“-ide”。例如，钠和氯形成氯化钠。
When a compound contains more than two elements and one of them is oxygen, the name often ends in ‘-ate’. Calcium carbonate (CaCO₃) contains calcium, carbon and oxygen.
当化合物含有两种以上元素且其中之一为氧时，其名称常以“-ate”结尾。碳酸钙（CaCO₃）含有钙、碳和氧。
A subscript number in a formula indicates how many atoms of the element just before it are present. No subscript means just one atom.
化学式中的下标数字表示它前面那一种元素的原子数目。没有下标则表示只有一个原子。
Using brackets in a formula, like Ca(OH)₂, means the OH group is taken twice. This shows that there are two oxygen atoms and two hydrogen atoms in addition to one calcium atom.
在公式中使用括号，如 Ca(OH)₂，表示 OH 基团要乘以2。这表示除了一个钙原子外，还有两个氧原子和两个氢原子。
3. Pure Substances, Mixtures and Separation | 纯物质、混合物与分离
A pure substance consists of a single element or compound with a fixed melting point and boiling point. Any impurity will lower the melting point and broaden its range.
纯物质由单一元素或化合物组成，具有固定的熔点和沸点。任何杂质会降低熔点并使熔程变宽。
A mixture contains two or more substances that are not chemically joined together. The components retain their own properties and can be separated by physical methods.
混合物含有两种或多种未通过化学键结合的物质。各组分保持各自的性质，并可以通过物理方法分离。
Filtration is used to separate an insoluble solid from a liquid. The liquid that passes through the filter paper is called the filtrate, while the solid left behind is the residue.
过滤用于将不溶性固体从液体中分离出来。穿过滤纸的液体称为滤液，留在滤纸上的固体是残渣。
Evaporation and crystallisation are methods to obtain a dissolved solid from a solution. The solvent evaporates, leaving the solid behind as crystals when the solution reaches saturation.
蒸发和结晶是从溶液中获取溶解的固体的方法。溶剂蒸发后，当溶液达到饱和时，固体就会以晶体形式析出。
Simple distillation is used to separate a solvent from a solution. The solvent boils off, its vapour travels through a condenser where it cools and turns back into a liquid called the distillate.
简单蒸馏用于从溶液中分离溶剂。溶剂沸腾汽化，蒸汽经过冷凝器冷却后重新变成液体，称为馏出液。
Chromatography separates mixtures of coloured substances. Each substance moves up the paper at a different speed, producing a distinctive pattern called a chromatogram.
色谱法用于分离有色物质的混合物。每种物质在纸上以不同的速度向上移动，产生称为色谱图的独特图案。
Filtration does not separate dissolved substances. Only methods like distillation or crystallisation can recover a solid that is fully dissolved in a liquid.
过滤不能分离溶解的物质。只有像蒸馏或结晶这样的方法才能从完全溶解的液体中回收固体。
4. Physical and Chemical Changes | 物理变化与化学变化
A physical change alters the appearance or state of a substance but does not create any new products. Changes of state, such as melting, boiling, freezing and condensing, are all physical.
物理变化改变物质的外观或状态，但不生成任何新产物。状态变化，如熔化、沸腾、凝固和凝结，均属于物理变化。
A chemical change, or chemical reaction, produces one or more new substances with different properties from the reactants. Signs include colour change, gas production, temperature change and formation of a precipitate.
化学变化，即化学反应，生成一种或多种与反应物性质不同的新物质。迹象包括颜色变化、气体产生、温度变化以及沉淀形成。
The Law of Conservation of Mass states that the total mass of the reactants equals the total mass of the products. Atoms are rearranged, but none are created or destroyed.
质量守恒定律指出，反应物的总质量等于生成物的总质量。原子被重新排列，但没有原子被创造或消灭。
An exothermic reaction transfers energy to the surroundings, often causing a temperature rise. Combustion and neutralisation are typical exothermic reactions.
放热反应向环境释放能量，通常导致温度升高。燃烧和中和反应是典型的放热反应。
An endothermic reaction takes in energy from the surroundings, causing a temperature drop. Thermal decomposition and photosynthesis are endothermic processes.
吸热反应从环境吸收能量，导致温度下降。热分解和光合作用属于吸热过程。
Physical changes are usually easier to reverse than chemical changes. For instance, water freezing into ice can be reversed by heating, but baking a cake cannot be ‘unbaked’.
物理变化通常比化学变化更容易逆转。例如，水结成冰可通过加热逆转，但烤好的蛋糕不能“变回”原来的面糊。
5. Chemical Reactions and Equations | 化学反应与方程式
In a word equation, the names of the reactants are written on the left and the products on the right, separated by an arrow. The arrow means ‘react to form’.
在文字方程式中，反应物名称写在左边，生成物名称写在右边，中间用箭头隔开。箭头表示“反应生成”。
A symbol equation uses chemical formulae to show the reaction. The equation must be balanced so that the number of atoms of each element is the same on both sides.
符号方程式用化学式来表示反应。方程式必须配平，使每种元素的原子在两边数目相等。
Combustion is the reaction of a fuel with oxygen, producing oxides and releasing energy. Complete combustion of a hydrocarbon produces carbon dioxide and water.
燃烧是燃料与氧气的反应，生成氧化物并释放能量。碳氢化合物完全燃烧生成二氧化碳和水。
Thermal decomposition breaks down a compound into simpler substances when heated. For example, calcium carbonate decomposes into calcium oxide and carbon dioxide.
热分解是指化合物受热时分解成更简单的物质。例如，碳酸钙分解为氧化钙和二氧化碳。
Oxidation is a reaction in which a substance gains oxygen. Reduction is the opposite process, where a substance loses oxygen. These two always occur together.
氧化是物质得到氧的反应。还原是相反的过程，物质失去氧。这两者总是同时发生。
A catalyst is a substance that speeds up a chemical reaction without being used up itself. Manganese dioxide acts as a catalyst for the decomposition of hydrogen peroxide.
催化剂是一种能加快化学反应速率而自身不被消耗的物质。二氧化锰可作为过氧化氢分解的催化剂。
The symbol (s) means solid, (l) liquid, (g) gas and (aq) aqueous, which is a substance dissolved in water. State symbols are added after each formula in a symbol equation.
符号 (s) 表示固体，(l) 液体，(g) 气体，(aq) 为水溶液，即物质溶解在水中。在符号方程式中，每种化学式后面都要标注状态符号。
6. Acids, Alkalis and Indicators | 酸、碱与指示剂
An acid is a substance that releases hydrogen ions (H⁺) when dissolved in water. Common laboratory acids include hydrochloric acid, sulfuric acid and nitric acid.
酸是溶于水时释放氢离子（H⁺）的物质。常见的实验室酸包括盐酸、硫酸和硝酸。
An alkali is a soluble base that releases hydroxide ions (OH⁻) in water. Sodium hydroxide and potassium hydroxide are common alkalis. Beware: not all bases are alkalis, but all alkalis are bases.
碱是一种可溶性的盐基，在水中释放氢氧根离子（OH⁻）。氢氧化钠和氢氧化钾是常见的碱。注意：并非所有盐基都是碱，但所有碱都是盐基。
The pH scale runs from 0 to 14 and measures how acidic or alkaline a solution is. Values below 7 are acidic, 7 is neutral, and values above 7 are alkaline.
pH 标度范围从0到14，衡量溶液的酸碱程度。pH 值低于7为酸性，7为中性，高于7为碱性。
Indicators are substances that change colour depending on pH. Litmus paper turns red in acid and blue in alkali. Universal indicator gives a full range of colours and allows you to estimate the pH to the nearest whole number.
指示剂是根据 pH 值改变颜色的物质。石蕊试纸在酸性中变红，在碱性中变蓝。通用指示剂显示一系列颜色，可让你估计 pH 值到最接近的整数。
A neutralisation reaction occurs when an acid reacts with an alkali to form a salt and water. The general word equation is: acid + base → salt + water.
中和反应是酸与碱反应生成盐和水的过程。一般的文字方程式为：酸 + 碱 → 盐 + 水。
When naming the salt produced in a neutralisation, the first part comes from the metal (or ammonium) in the base, and the second part from the acid. Hydrochloric acid produces chlorides, sulfuric acid produces sulfates and nitric acid produces nitrates.
在中和反应生成的盐的命名中，第一部分来自碱中的金属（或铵），第二部分来自酸。盐酸生成氯化物，硫酸生成硫酸盐，硝酸生成硝酸盐。
Only a few drops of universal indicator are needed to test pH. Using too much can contaminate the solution and affect the colour change.
检测 pH 值只需几滴通用指示剂。使用过多会污染溶液并影响颜色变化。
7. The Reactivity Series and Displacement | 金属活动性顺序与置换
The reactivity series lists metals in order of how vigorously they react with substances such as oxygen, water and acids. Potassium, sodium and lithium are among the most reactive, while gold and platinum are the least reactive.
金属活动性顺序将金属按其与氧气、水和酸等物质反应的剧烈程度排列。钾、钠和锂是最活泼的，而金和铂最不活泼。
A more reactive metal can displace a less reactive metal from its compound. For example, when magnesium ribbon is placed in copper sulfate solution, the blue colour fades and brown copper metal deposits because magnesium displaces copper.
较活泼的金属能将较不活泼的金属从其化合物中置换出来。例如，将镁带放入硫酸铜溶液中，蓝色逐渐褪去并析出红棕色的铜金属，因为镁置换了铜。
The thermite reaction is a spectacular displacement reaction where aluminium displaces iron from iron oxide, producing molten iron. It demonstrates how a more reactive metal can extract a less reactive one from its oxide.
铝热反应是一个壮观的置换反应，铝从氧化铁中置换出铁，生成熔融的铁。它展示了更活泼的金属如何从氧化物中提取出较不活泼的金属。
Metals react with acids to produce a salt and hydrogen gas. The faster the bubbles of hydrogen are produced, the higher the metal is in the reactivity series.
金属与酸反应生成盐和氢气。产生氢气气泡的速度越快，该金属在活动性顺序中的位置就越高。
Carbon is often included in the reactivity series because it can extract metals from their oxides if the metal is less reactive than carbon. This is how iron is extracted from iron ore in a blast furnace.
碳常被列入活动性顺序中，因为如果金属的活泼性低于碳，碳就可以从金属氧化物中将其提取出来。高炉冶铁正是利用这一原理。
The acronym OIL RIG helps to remember redox reactions: Oxidation Is Loss (of electrons), Reduction Is Gain (of electrons). In terms of oxygen transfer, a substance is oxidised when it gains oxygen and reduced when it loses oxygen.
缩略词 OIL RIG 有助于记忆氧化还原反应：氧化是失去电子，还原是得到电子。以氧的转移来说，得到氧的物质被氧化，失去氧的物质被还原。
8. States of Matter and Particle Theory | 物质状态与粒子理论
All matter is made up of tiny particles that are constantly in motion. The arrangement, movement and energy of these particles determine whether a substance is a solid, liquid or gas.
所有物质都由不断运动的微小粒子构成。这些粒子的排列、运动和能量决定了物质是固体、液体还是气体。
In solids, particles are arranged in a regular, fixed pattern and vibrate in place. Strong forces hold them close together, giving solids a definite shape and volume.
固体中，粒子排列成规则、固定的模式并在原地振动。强大的作用力使它们紧紧靠在一起，使固体具有确定的形状和体积。
In liquids, particles are close together but can slide past each other. A liquid has a fixed volume but takes the shape of its container.
液体中，粒子彼此靠近但可以相互滑动。液体具有固定的体积，但形状随容器改变。
In gases, particles are far apart and move rapidly in all directions. Gases have no fixed shape or volume; they spread out to fill any container completely.
气体中，粒子相距很远并快速向各个方向运动。气体没有固定的形状或体积；它们会扩散并完全充满任何容器。
Melting is the change from solid to liquid at the melting point. Boiling (or evaporation) is the change from liquid to gas. During a change of state, the temperature stays constant while the forces between particles are overcome.
熔化是在熔点时从固态变为液态的过程。沸腾（或蒸发）是从液态变为气态。在状态变化期间，当粒子间的力被克服时，温度保持恒定。
Diffusion is the net movement of particles from an area of higher concentration to an area of lower concentration. It is fastest in gases because particles are free to move quickly.
扩散是粒子从高浓度区域向低浓度区域的净移动。扩散在气体中最快，因为粒子可以自由快速地运动。
When a substance changes state, it is a physical change because no new chemical substances are made. Melting ice results in water – both have the same formula H₂O.
物质状态变化时，由于没有新的化学物质生成，因此是物理变化。冰融化得到水——二者化学式都是 H₂O。
9. Acids and Bases: A Closer Look at Reactions | 酸与碱：反应深入篇
Not all bases are alkalis. A base is any substance that can neutralise an acid, but only soluble bases are called alkalis. Copper oxide is a base, but not an alkali because it does not dissolve.
并非所有盐基都是碱。盐基是任何能中和酸的物质，但只有可溶性的盐基才称为碱。氧化铜是一种盐基，但不是碱，因为它不溶于水。
Metal oxides and metal hydroxides are typical bases. When they react with acids, they form a salt and water only – no extra gases are produced unless the base is a carbonate.
金属氧化物和金属氢氧化物是典型的盐基。它们与酸反应时仅生成盐和水——除非盐基是碳酸盐，否则不会产生额外的气体。
Carbonates react with acids to produce a salt, water and carbon dioxide gas. The fizzing (effervescence) is a clear sign that a carbonate is present. Testing with limewater turns it milky, confirming carbon dioxide.
碳酸盐与酸反应生成盐、水和二氧化碳气体。冒泡（泡腾）是碳酸盐存在的明显迹象。用石灰水检测，石灰水变浑浊即可确认二氧化碳。
When making a soluble salt by reacting an acid with an insoluble base like copper oxide, the base must be added in excess until no more dissolves. The excess solid is then removed by filtration.
用酸与不溶性盐基（如氧化铜）反应制备可溶性盐时，必须将盐基过量加入，直到不再溶解为止。然后通过过滤除去多余的固体。
Evaporating the filtrate gently produces crystals of the salt. Rapid heating can cause the salt to splatter or decompose, so slow evaporation over a water bath is safer.
将滤液缓缓蒸发可以得到盐的晶体。快速加热可能导致盐飞溅或分解，因此用水浴缓慢蒸发更为安全。
Strong acids (like hydrochloric, sulfuric and nitric acids) fully ionise in water, releasing many hydrogen ions. Weak acids like citric acid or ethanoic acid only partially ionise, so they have higher pH values for the same concentration.
强酸（如盐酸、硫酸和硝酸）在水中完全电离，释放出大量氢离子。弱酸如柠檬酸或乙酸仅部分电离，因此在相同浓度下它们的 pH 值较高。
10. Metal Extraction and Environmental Aspects | 金属提取与环境问题
Unreactive metals such as gold are found in the Earth’s crust in their native state because they do not combine easily with other elements. Most metals, however, are found as ores – compounds mixed with rocky material.
不活泼的金属如金，以天然状态存在于地壳中，因为它们不易与其他元素结合。然而，大多数金属以矿物的形式存在——即化合物与岩石物质的混合物。
An ore is a rock that contains enough of a metal compound to make it worth extracting economically. Iron ore, mainly haematite (Fe₂O₃), is the most common source of iron.
矿石是含有足够多金属化合物、在经济上值得提取的岩石。铁矿石，主要是赤铁矿（Fe₂O₃），是最常见的铁来源。
Extraction methods depend on a metal’s position in the reactivity series. Metals more reactive than carbon are extracted by electrolysis of their molten compounds, while those less reactive can be extracted by heating with carbon.
提取方法取决于金属在活动性顺序中的位置。比碳更活泼的金属通过电解其熔融化合物来提取，而较不活泼的则可用碳加热还原提取。
Electrolysis requires large amounts of electrical energy, making it expensive. This is why reactive metals like aluminium are more costly to produce than iron.
电解需要大量电能，因此成本高昂。这就是为什么像铝这样的活泼金属生产成本高于铁。
Recycling metals saves energy and reduces the need for mining. It also limits the amount of waste sent to landfill and helps conserve finite resources.
回收金属可以节约能源并减少开采需求。它还减少了送往垃圾填埋场的废物数量，有助于保护有限资源。
Bioleaching and phytomining are new methods that use bacteria or plants to extract metals from low-grade ores. These biotechnologies are slower but less damaging to the environment than traditional mining.
生物浸出和植物采矿是利用细菌或植物从低品位矿石中提取金属的新方法。这些生物技术速度较慢，但对环境的破坏比传统开采小。
The blast furnace process for iron extraction requires limestone, coke and haematite. Limestone removes sandy impurities by forming molten slag, which floats on top of the iron.
高炉炼铁工艺需要石灰石、焦炭和赤铁矿。石灰石通过形成熔融的炉渣去除沙状杂质，炉渣会浮在铁水表面。
11. Bonding and Structure Overview | 化学键与结构概览
Atoms bond together to achieve a full outer electron shell, making them more stable. This is the octet rule – the tendency to have eight electrons in the outer shell, like the noble gases.
原子通过键合达到满的最外电子层，从而使自身更加稳定。这就是八隅律——倾向于像稀有气体那样最外层具有八个电子。
Ionic bonding occurs between metals and non-metals. Metals lose electrons to form positive ions (cations), while non-metals gain electrons to form negative ions (anions). The opposite charges attract strongly.
离子键发生在金属与非金属之间。金属失去电子形成阳离子（正离子），非金属得到电子形成阴离子（负离子）。相反电荷相互强烈吸引。
Covalent bonding takes place between non-metal atoms. They share pairs of electrons so that each atom achieves a full outer shell. Small covalent molecules like H₂O and CO₂ have low melting points because the forces between molecules are weak.
共价键发生在非金属原子之间。它们共享电子对，从而使每个原子达到满外层。像 H₂O 和 CO₂ 这样的小分子共价化合物熔点较低，因为分子之间的作用力很弱。
Giant covalent structures, such as diamond and silicon dioxide, have many atoms joined by covalent bonds in a continuous network. They have very high melting points and are extremely hard.
巨型共价结构，如金刚石和二氧化硅，许多原子通过共价键连接成连续的网络。它们的熔点极高而且极其坚硬。
Metallic bonding involves a regular lattice of positive metal ions surrounded by a ‘sea’ of delocalised electrons. This explains why metals conduct electricity and heat, and can be bent or hammered into shape without breaking.
金属键涉及正金属离子的规则晶格，被离域电子的“海洋”包围。这就解释了为什么金属能够导电、导热，并且可以被弯曲或锤打成各种形状而不断裂。
In simple ionic compounds, the formula reflects the ratio of ions needed to balance the charges. For example, magnesium oxide is MgO because Mg²⁺ balances O²⁻, whereas sodium chloride is NaCl because Na⁺ balances Cl⁻.
在简单离子化合物中，化学式体现了平衡电荷所需的离子比率。例如，氧化镁是 MgO，因为 Mg²⁺ 与 O²⁻ 平衡；而氯化钠是 NaCl，因为 Na⁺ 与 Cl⁻ 平衡。
You can draw ‘dot and cross’ diagrams to model ionic or covalent bonding. Only the outer shell electrons are shown, using dots for one atom and crosses for the other to track where they come from.
你可以绘制“点叉图”来模拟离子键或共价键。只显示最外层电子，用一个原子的点、另一个原子的叉来标示电子的来源。
12. Rates of Reaction and Energetics | 反应速率与能量变化
The rate of a chemical reaction tells you how quickly reactants are converted into products. A fast reaction, like an explosion, finishes in a fraction of a second; rusting is very slow.
化学反应的速率说明反应物转化为生成物的快慢。快速反应，如爆炸，在几分之一秒内完成；而铁生锈则非常慢。
Increasing the temperature increases the rate of reaction because particles move faster and collide more often with greater energy. More collisions meet the activation energy needed for a reaction to occur.
升高温度会提高反应速率，因为粒子运动得更快，碰撞更频繁且能量更高。更多的碰撞达到了反应发生所需的活化能。
Increasing the concentration of reactants in a solution, or the pressure of gaseous reactants, also raises the rate because there are more particles per unit volume, leading to more frequent collisions.
增大溶液中反应物的浓度或气体反应物的压强也会提高反应速率，因为单位体积内的粒子数增多，导致碰撞更加频繁。
Breaking a solid reactant into smaller pieces (increasing the surface area) exposes more particles to react at any time, speeding up the reaction. A powder reacts faster than large lumps.
将固体反应物破碎成小块（增大表面积）能使更多粒子随时参与反应，从而加快反应速度。粉末比大块固体反应更快。
Catalysts provide an alternative reaction pathway with a lower activation energy. They remain chemically unchanged at the end of the reaction and are not included in the overall equation.
催化剂提供了活化能较低的替代反应路径。它们在反应结束时化学性质不变，不会出现在总方程式中。
In an energy profile diagram, the difference between the energy of the reactants and the products shows whether the reaction is exothermic (products have lower energy) or endothermic (products have higher energy). The peak represents the activation energy.
在能级图中，反应物与生成物之间的能量差值表明反应是放热（生成物能量较低）还是吸热（生成物能量较高）。峰值代表活化能。
You can measure the rate of a reaction by recording the volume of gas produced at regular time intervals, or by measuring the loss of mass as a gas escapes. Plotting a graph helps you compare rates.
你可以通过每隔一定时间记录产生的气体体积，或测量由于气体逸出而导致的质量减少来测定反应速率。绘制图表有助于比较速率。
Published by TutorHao | Chemistry Revision Series | aleveler.com
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