Introducing Elements | 元素入门

📚 Introducing Elements | 元素入门

Look around the room and you will see materials such as wood, glass, plastic, metal, water and air. Chemistry begins with a simple but powerful idea: all of these materials are built from a relatively small number of basic substances called elements. In this topic, you will learn what an element is, how elements are represented by symbols, how they are organised in the periodic table, and how their properties help us use them in everyday life.

环顾四周，你会看到木材、玻璃、塑料、金属、水和空气等材料。化学始于一个简单而强大的观点：所有这些材料都是由相对少量的基本物质——元素构成的。在本主题中，你将学习什么是元素、元素如何用符号表示、元素如何在周期表中排列，以及它们的性质如何帮助我们在日常生活中使用它们。

1. What Is an Element? | 什么是元素？

An element is a pure substance made from only one type of atom. For example, a piece of pure iron contains only iron atoms, and a balloon filled with pure oxygen contains only oxygen atoms. Elements are the simplest chemical substances because they cannot be broken down into simpler substances by ordinary chemical reactions.

元素是仅由一种原子组成的纯物质。例如，一块纯铁只含有铁原子，充满纯氧气的气球只含有氧原子。元素是最简单的化学物质，因为它们不能通过普通的化学反应被分解成更简单的物质。

Some familiar elements include iron, oxygen, gold, carbon, hydrogen, copper and aluminium. The air you breathe is a mixture containing the elements oxygen and nitrogen. The aluminium used to make a drinks can is also an element. Altogether, around 118 elements have been discovered, and every material in the universe is made from one element or from combinations of elements.

一些熟悉的元素包括铁、氧、金、碳、氢、铜和铝。你呼吸的空气是含有氧元素和氮元素的混合物。用来制造饮料罐的铝也是一种元素。人类总共发现了约 118 种元素，宇宙中的每一种物质都由一种元素或多种元素的组合构成。

An element is therefore the simplest building block of chemistry. It is not the same as an atom, but an element is the name we give to a substance made of one kind of atom. Understanding this difference will help you in every later chemistry topic.

因此，元素是化学最简单的构建单元。元素并不等同于原子，但元素是我们给仅由一种原子组成的物质起的名称。理解这一区别将有助于你学习以后的所有化学主题。

2. Atoms: The Building Blocks of Elements | 原子：元素的基本构建单元

An atom is the smallest particle of an element that still has the chemical properties of that element. If you could cut a piece of gold into smaller and smaller pieces, the smallest piece that still behaves like gold would be a single gold atom.

原子是元素中仍具有该元素化学性质的最小粒子。如果你能把一块金子切成越来越小的碎块，仍表现为金的最小碎块就是一个金原子。

Each element has its own unique atoms. Oxygen atoms are different from carbon atoms, and carbon atoms are different from iron atoms. These differences explain why elements have different properties, such as appearance, melting point and reactivity.

每种元素都有自己独特的原子。氧原子不同于碳原子，碳原子不同于铁原子。这些差异解释了为什么元素具有不同的性质，例如外观、熔点和反应活性。

At KS3 level, it is useful to know that atoms themselves are made of even smaller particles: protons, neutrons and electrons. The number of protons in an atom determines which element it is. All oxygen atoms have eight protons, while all carbon atoms have six protons.

在 KS3 阶段，了解原子本身由更小的粒子——质子、中子和电子组成是很有用的。原子中的质子数决定了它是哪种元素。所有氧原子都有 8 个质子，而所有碳原子都有 6 个质子。

3. Chemical Symbols | 化学符号

Scientists use chemical symbols as a short way to write the names of elements. A symbol always starts with a capital letter; if there is a second letter, it is written in lowercase. For example, the symbol for oxygen is O, not o, and the symbol for calcium is Ca, not CA.

科学家用化学符号作为元素名称的简便写法。符号始终以大写字母开头；如果有第二个字母，则用小写字母书写。例如，氧的符号是 O 而不是 o，钙的符号是 Ca 而不是 CA。

Most symbols come from the element’s English or Latin name. This is why some symbols do not match the English name at all. Learning the common symbols early makes chemical equations and formulae much easier to read later.

大多数符号来自元素的英文名或拉丁名。这就是为什么有些符号与英文名称完全不对应。尽早学习常见符号会让你以后更容易读写化学方程式和化学式。

• C = carbon 碳
• O = oxygen 氧
• H = hydrogen 氢
• N = nitrogen 氮
• S = sulfur 硫
• Fe = iron 铁（来自拉丁名 ferrum）
• Cu = copper 铜（来自拉丁名 cuprum）
• Na = sodium 钠（来自拉丁名 natrium）
• K = potassium 钾（来自拉丁名 kalium）
• Au = gold 金（来自拉丁名 aurum）
• Ag = silver 银（来自拉丁名 argentum）
• Pb = lead 铅（来自拉丁名 plumbum）

Try to learn symbols in pairs with their names. For example, when you see Fe

Published by TutorHao | KS3 Chemistry Revision Series | aleveler.com

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