90 Mixing Matter-Mid

Mixing Matter Written by David Dreier

戴维·德雷尔著

Introduction Look at the things around you. Maybe you see books and a desk. What are they made of? The books are probably made of paper. The desk could be made of materials such as wood, glass, metal, or plastic. Maybe it's made of several materials put together. All these objects and materials are types of matter. Everything that takes up space and has weight is made of matter. But what is matter? This book explores the types of matter, how those materials can be mixed to make new things, and how matter can change.

看看你周围的事物。 也许你会看到书和一张桌子。 它们是用什么做的?这些书可能是纸做的。 桌子可以用木头、玻璃、金属或塑料等材料制成。 也许它是由几种材料组合而成的。 所有这些物体和物质都是物质的类型。 任何占据空间和有重量的东西都是由物质构成的。 但是什么是物质呢?这本书探讨了物质的类型，这些材料是如何混合形成新事物的，以及物质是如何变化的。

Elements All matter is made of simple materials called elements. An element is a substance that cannot be broken down into other substances. Imagine cutting a piece of gold into smaller and smaller pieces. No matter how small you make the pieces, each one will still be gold. That is why gold is an element. Word Wise Some symbols for elements come from the Latin language. For example, Fe is the symbol for iron. Fe is short for ferrum, the Latin word for iron.

所有物质都是由称为元素的简单物质构成的。 元素是一种不能分解成其他物质的物质。 想象一下把一块金子切成越来越小的碎片。 不管你做得多小，每一块都是金子。 这就是为什么金是一种元素。 一些表示元素的符号来自拉丁语。 例如，Fe是铁的符号。 Fe是拉丁文中铁的缩写ferrum。

There are about 120 elements. Some are metals, such as iron and gold. Others are usually gases, such as oxygen and helium. Each element has a symbol. The symbol is one or two letters that are often short for the element's name. For example, oxygen is "O" and helium is "He." Elements combine in different ways to make materials that we see and use every day.

大约有120种元素。 有些是金属，如铁和金。 其他的通常是气体，如氧和氦。 每个元素都有一个符号。 该符号通常是元素名称的缩写，由一两个字母组成。 例如，氧是“O”，氦是“He”。 元素以不同的方式组合成我们每天看到和使用的材料。

Atoms Imagine that you could look deep inside any object. You would see that everything is made of tiny particles called atoms. Atoms are so small that they can only be seen with strong microscopes. Every element is made of a certain kind of atom. And no two elements have atoms that are the same. The smallest piece of gold is a gold atom. If you could look even deeper inside an atom, you'd see that it is made of even smaller particles. An atom is a little like the solar system. In the solar system, planets circle the Sun. In an atom particles called electrons circle the center of the atom, The center of the atom. is called the nucleus Particles called protons and neutrons. are found in the nucleus.

想象一下，你可以看到任何物体的内部深处。 你会看到一切都是由叫做原子的微小粒子组成的。 原子是如此之小，只有用高倍显微镜才能看到。 每种元素都是由某种原子构成的。 没有两个元素的原子是相同的。 最小的黄金是金原子。 如果你能更深入地观察原子内部，你会发现它是由更小的粒子组成的。 原子有点像太阳系。 在太阳系中，行星围绕太阳运行。 在一个原子中，叫做电子的粒子围绕着原子的中心，原子的中心。 叫做原子核粒子叫做质子和中子。 都存在于细胞核中。

All atoms of the same element have the same number of protons and electrons. (The number of neutrons sometimes changes.) But atoms of different elements contain different numbers of protons and electrons. Even though particles are far too tiny to see, they still weigh something. The more protons and neutrons an atom has, the more it will weigh. Helium atoms have just 2 protons and 2 neutrons in their nucleus. But lead has 82 protons and 125 neutrons. So lead is much heavier than helium.

同一元素的所有原子都有相同数量的质子和电子。 (中子数有时会变化。)但是不同元素的原子含有不同数量的质子和电子。 即使粒子小到看不见，它们仍然有重量。 一个原子的质子和中子越多，它的重量就越大。 氦原子的原子核中只有2个质子和2个中子。 但是铅有82个质子和125个中子。 所以铅比氦重得多。