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  • 金属

    A person pours shiny liquid mercury from a beaker into a Petri dish.

    When you think of metals, do you think of objects such as iron nails and gold jewelry? If so, it might surprise you to learn that the shiny pouring out of the  beaker in the photo above is also a metal . It’s called mercury, and it’s the only metal that normally exists on Earth as a liquid. Just what are metals, and what are their properties? Read on to find out.
    ::当你想到金属时,你会想到铁钉和金首饰等物件吗?如果是这样的话,你可能会惊讶地知道上面照片中烧杯中的亮光也是一种金属。 它被称为汞,是地球上唯一通常以液体形式存在的金属。 金属是什么,它们的特性是什么? 阅读看看。

    What Are Metals?
    ::"金属"是什么?

    Metals are that can conduct electricity. They are one of three classes of elements (the other two classes are and metalloids). Metals are by far the largest of the three classes. In fact, most elements are metals. All of the elements on the left side and in the middle of the periodic table , except for hydrogen, are metals. There are several different types of metals, including alkali metals in group 1 of the periodic table, in group 2, and in groups 3–12. The majority of metals are transition metals.
    ::金属是能够进行电力的金属,是三种元素之一(其他两类为和金属类),金属是三大元素中最大的。事实上,多数元素是金属。除氢外,在周期表左侧和中间的所有元素都是金属。有几种不同类型的金属,包括周期表第1组、第2组和第3至12组的碱性金属。大多数金属是过渡性金属。

    Properties of Metals
    ::金属属性

    Elements in the same class share certain basic similarities. In addition to conducting electricity, many metals have several other shared properties, including those listed below. 
    ::同一类中的元素有某些基本相似之处,许多金属除了用电以外,还具有其他几种共有特性,包括以下所列特性。

    • Metals have relatively high points. This explains why all metals except for mercury are solids at room .
      ::金属的浓度相对较高,这解释了为什么除汞以外的所有金属都是室内固体的原因。
    • Most metals are good conductors of . That’s why metals such as iron, copper, and aluminum are used for pots and pans.
      ::大部分金属都是很好的导体。 这就是为什么铁、铜和铝等金属被用于锅和锅。
    • Metals are generally shiny. This is because they reflect much of the light that strikes them. The mercury pictured above is very shiny.
      ::金属一般都是闪亮的,这是因为金属反映了许多撞击它们的亮光。上面所描绘的汞非常闪亮。
    • The majority of metals are ductile. This means that they can be pulled into long, thin shapes, like the aluminum electric wires pictured in the Figure .
      ::大部分金属是粘性金属。这意味着它们可以被拉入长细的形状,如图中的铝电线。
    • Metals tend to be malleable. This means that they can be formed into thin sheets without breaking. An example is aluminum foil, also pictured in the Figure .
      ::金属往往是易变易变的。 这意味着金属可以不折不扣地形成薄薄的薄板。 一个例子是铝粉,图中也有图解。

    Examples of aluminum: coiled wire on the left and sheet foil on the right.

    Metals are malleable, meaning they can be deformed into many shapes. Aluminum is a very malleable metal that can be drawn into wires (A) or flattened into sheets (B).
    ::金属是可移动的,意味着它们可以变形成多种形状。 铝是一种非常可移动的金属,可以被带入铁丝线(A ) 或被压入薄板(B ) 。

    Q: The defining characteristic of metals is their ability to conduct electricity. Why do you think metals have this property?
    ::问题:金属的决定性特征是它们进行电力的能力。你为什么认为金属有这种特性?

    A: The properties of metals—as well as of elements in the other classes—depend mainly on the number and arrangement of their electrons.
    ::A:金属和其他类别元素的特性主要取决于其电子的数量和安排。

    Explaining the Properties of Metals
    ::解释金属属性

    To understand why metals can conduct electricity, consider the metal lithium as an example. An of lithium is modeled below. Look at lithium’s electrons. There are two electrons at the first . This energy level can hold only two electrons, so it is full in lithium. The second energy level is another story. It can hold a maximum of eight electrons, but in lithium it has just one. A full outer energy level is the most stable arrangement of electrons. Lithium would need to gain seven electrons to fill its outer energy level and make it stable. It’s far easier for lithium to give up its one in energy level 2, leaving it with a full outer energy level (now level 1). Electricity is a flow of electrons. Because lithium (like most other metals) easily gives up its “extra” electron, it is a good conductor of electricity. This tendency to give up electrons also explains other properties of metals such as lithium.
    ::要了解金属为何可以进行电力,请将金属锂作为例子。下面将做一个锂模型。看看锂的电子。第一层有两种电子。这种能源水平只能维持两个电子,因此它是完整的锂。第二个能源水平是另一个故事。它最多能维持八个电子,但在锂中它只有一个。一个完整的外部能源水平是电子的最稳定的安排。锂需要获得七个电子来填充其外部能源水平并使其稳定。锂在2级中放弃一个电子要容易得多,而将其置于一个完整的外部能源水平(现为第1级 ) 。 因为锂(像大多数其他金属一样)很容易放弃其“外”电,它是一个良好的电导体。放弃电子的这种倾向也解释了其他金属的特性,比如锂。

    Summary
    ::摘要

    • Metals are elements that can conduct electricity. Most elements are metals.
      ::金属是能够发电的元素,大部分元素是金属。
    • All metals except for mercury are solids at room temperature. Many metals are shiny, ductile, and malleable. Most are also good conductors of heat.
      ::除汞外,所有金属都是室温下的固体,许多金属是闪亮的、粘附的和可移动的,大多数也是热导体。
    • Electricity is a flow of electrons. Atoms of metals tend to give up electrons, explaining why they are good conductors of electricity. The tendency to give up electrons also explains many of the other properties of metals.
      ::电是电子的流体。 金属原子倾向于放弃电子,解释为什么它们是良好的电力导体。 放弃电子的倾向也解释了金属的许多其他特性。

    Review
    ::回顾

    1. What are metals?
      ::什么是金属?
    2. List several properties of metals.
      ::列出金属的若干特性。
    3. Explain why metals can conduct electricity.
      ::解释为什么金属可以用电。

    Resources
    ::资源