Section outline

  • General

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  • 和

    A display of Russian nesting dolls with over thirty-five layers in various sizes.

    How many dolls are in this picture?
    ::这张照片里有多少个洋娃娃?

    Russian “nesting dolls” (often known as matryoshka dolls) have a long history in Russia.  These dolls are designed to nest inside of one another.  When we open the largest doll, we find a somewhat smaller doll inside it.  These dolls can often go down seven or eight layers.  The set seen above is unusual in that it has over thirty-five layers.
    ::俄罗斯的“内生娃娃 ” ( 通常被称为 matryoshka 娃娃 ) 在俄罗斯历史悠久。 这些洋娃娃设计成彼此内部的巢穴。 当我们打开最大的洋娃娃时, 我们发现其中的洋娃娃较小一些。 这些洋娃娃通常会从七到八层下沉。 上面的景象不同寻常, 因为它有35层以上 。

    Lanthandies and Actinides
    ::和

    We see some hidden “layers” in chemistry .  As we look at the periodic table below, we see two pink boxes – one between Ba ( 56) and Hf (element 72) and the other between Ra (88) and Rf (104).  These elements all have unfilled f -sublevels.  Because of the uniqueness of the configurations, these elements fit into the two boxes in the larger periodic table.
    ::我们看到化学界中隐藏的“层 ” 。 当我们看下个周期表时,我们看到两个粉红色盒子 — — 一个在巴( 56 ) 和赫夫( 元素 72 ) 之间,另一个在拉( 88 ) 和瑞夫( 104 ) 之间。 这些元素都具有未填充的f次级。 由于这些配置的独特性,这些元素可以融入较大周期表中的两个框中。

    As the number of elecrons in an increases, we begin to see some strange behaviors.  Due to the way the electron energy levels work, some inner levels fill after one or more outer levels do.  We see this in two similar groups of elements – the lanthanides and the actinides .
    ::随着电子元数的增加,我们开始看到一些奇怪的行为。 由于电子能源水平的运作方式,一些内部水平在一个或多个外部水平之后会填充。 我们从两种相似的元素组 — — lanthanides 和 adminides — — 中看到这一点。

    Periodic table highlighting lanthanides and actinides with their unique electron configurations.

    The f-Block
    ::F- 区块

    The first of the f sublevels to begin filling is the 4 f sublevel. It fills after the 6 s sublevel, meaning that f sublevels are two principal energy levels behind. The general electron configuration for elements in the f block is ( n -  2 )f 1-14 ns 2 . The seven of the f sublevel accommodate 14 electrons, so the f block is 14 elements in length. It is pulled out of the main body of the period table and is shown at the very bottom. Because of that, the elements of the f block do not belong to a group, being wedged in between Groups 3 and 4. The lanthanides are the 14 elements from cerium ( 58) to lutetium (atomic number 71). The word comes from the Greek “lanthanein” meaning “to be hidden.”  The name probably arose because these elements all hide behind one another in the periodic table. The 4 f sublevel is in the process of being filled for the lanthanides. They are all and are similar in reactivity to the Group 2 .
    ::开始填充的 f 子级别的第一个是 4f 子级别。 它在 6 子级别之后填充 f 子级别, 意思是 F 区块元素的一般电子配置是 (n - 2) f1-14ns2 。 f 区块中的 7 个包含 14 个电子, 因此 f 区块的长度是 14 个元素。 它从 周期表的主体中拉出, 并显示在底部 。 因此, f 区块的元素不属于一组, 介于 3 组和 4 组之间。 lanthanides 是 ( 58) 至 的 14 个元素( 原子编号 71 ) 。 这个词来自 希腊的“ lanthanein” , 意思是“ 隐藏 ” 。 可能是因为这些元素都隐藏在周期表内的另一个元素。 4f 子级别正在被填充 。 它们都与 2 组相似 。

    The actinides are the 14 elements from thorium (atomic number 90) to lawrencium (atomic number 103). The 5 f sublevel is in the process of being filled. The actinides are all radioactive elements and only the first four have been found naturally on Earth. All of the others have only been artificially made in the laboratory. The lanthanides and actinides together are sometimes called the inner .
    ::是从(原子编号90)到(原子编号103)的14个元素。5f子层正在填充过程中。是所有放射性元素,只有头4个是地球上自然发现的。其他所有元素都是在实验室中人工制造的。和有时被称为内部。

     

     

    Uses of Lanthanides
    ::Lantanids 用途的使用

    Lanthanides have been widely used as to impart strength and hardness to metals.  The main lanthanide used for this purpose is cerium, mixed with small amounts of lanthanum, neodymium, and praseodymium.  These metals are also widely used in the petroleum industry for refining of crude oil into gasoline products.
    ::硝胺化物被广泛用于给金属带来强度和硬度,主要用于此目的的,与少量的、和混合,这些金属也广泛用于石油工业,将原油提炼成汽油产品。

    An oil refinery with smoke stacks and mountains in the background.

    Oil refinery.
    ::炼油厂

    Erbium and other lanthanides are widely used in some optical devices, such as night vision goggles, laser beams, and phosphorescent materials.
    ::一些光学设备,如夜视镜、激光束和磷光材料,广泛使用和其他。

    A person wearing night vision goggles, with a focus on their illuminated eye.

    Night vision goggles.
    ::夜视镜

    Uses of Actinides

    ::的用途

    The actinides are valuable primarily because they are radioactive.  These elements can be used as energy sources for applications as varied as cardiac pacemakers and generation of electrical energy for instruments on the moon. Uranium and plutonium have been employed in nuclear weapons and in plants.
    ::这些元素可以用作各种应用的能源,例如心脏心律起搏器和在月球上制造仪器的电能。 铀和钚被用于核武器和工厂。

    A cardiac pacemaker beside a ruler, illustrating its size and design.

    Pacemaker.
    ::搅拌机

    Summary

    ::摘要

    • Lanthanides and actinides are elements with unfilled f orbitals.
      ::和是含有未填充轨道 fal的元素。
    • Lanthanides are all metals with reactivity similar to group 2 elements.
      ::胺是所有具有与第2组元素类似的反应力的金属。
    • Actinides are all radioactive elements.
      ::是所有放射性元素。
    • Lanthanides are used in optical devices (night vision goggles), petroleum refining, and alloys.
      ::Lanthanides用于光学装置(夜视镜)、石油提炼和合金。
    • Actinides are found primarily in applications where their radioactivity can be used to power devices such as cardiac pacemakers.
      ::助燃剂主要见于其放射性可用于心脏心脏起搏器等动力装置的应用中。

    Review
    ::回顾

    1. What electron sublevel is being filled in the lanthanides?
      ::胺中填充的 电子分层是多少?
    2. What electron sublevel is being filled in the actinides?
      ::类中填充的 电子分层是多少?
    3. What sublevel is filled just prior to the filling of this sublevel?
      ::在填补该子级别之前,哪个子级别已经填补?
    4. Which actinides are found naturally on earth?
      ::地球上自然发现哪种?
    5. List some uses for lanthanides.
      ::列出安非他明的一些用途。
    6. List some uses for actinides.
      ::列出的用途。