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  • Aufbau原则

    Construction site of a building with scaffolding and palm trees in the foreground.

    How are buildings constructed?
    ::建筑物是如何建造的?

    Construction of a building begins at the bottom. The foundation is laid and the building goes up step by step. You obviously cannot start with the roof since there is no place to hang it. The building goes from the lowest level to the highest level in a systematic way.
    ::建筑物的建造从底部开始, 地基已经打好, 建筑物也一步一步往上。 您显然无法从屋顶开始, 因为没有地方可以挂起。 建筑系统化地从最低层到最高层。

    Aufbau Principle
    ::Aufbau原则

    In order to create ground state configurations for any , it is necessary to know the way in which the atomic sublevels are organized in order of increasing energy . Figure shows the order of increasing energy of the sublevels.
    ::为了为任何物体创建地面状态配置,必须了解原子子层的组织方式,以便增加能量。图显示子层能量增加的顺序。

    Graph showing the order of increasing energy of atomic sublevels with orbitals and color coding.

    Electrons are added to atomic orbitals in order from low energy (bottom of graph) to high (top of graph) according to the Aufbau principle. Principal energy levels are color coded, while sublevels are grouped together and each circle represents an orbital capable of holding two electrons.
    ::根据Aufbau原则,在原子轨道中增加电,从低能(图底)到高能(图顶),主要能量水平为彩色编码,次级分组,每个圆是一个能够持有两个电子的轨道。

    The lowest energy sublevel is always the 1 s sublevel, which consists of one . The single electron of the hydrogen will occupy the 1 s orbital when the atom is in its ground state. As we proceed with atoms with multiple electrons, those electrons are added to the next lowest sublevel: 2 s , 2 p , 3 s , and so on. The Aufbau principle states that an electron occupies orbitals in order from lowest energy to highest. The Aufbau (German: “building up, construction”) principle is sometimes referred to as the “building-up” principle. It is worth noting that in reality atoms are not built by adding and electrons one at a time and that this method is merely an aid for us to understand the end result.
    ::最小的能量子层始终是1子层,它由1组成。当原子处于地面状态时,氢的单电子将占据1轨道。当我们用多个电子进行原子时,这些电子将被添加到下一个最低的子层:2、2p、3s等。奥夫巴乌原则指出,从最低能量到最高能量,电子占据轨道。Aufbau(德国语:“建设、建设”)原则有时被称为“建设”原则。值得指出的是,在现实中,原子不是通过一次加增和电来建造的,这种方法只是帮助我们了解最终结果的帮助。

    As seen in  Figure , the energies of the sublevels in different principal energy levels eventually begin to overlap. After the 3 p sublevel, it would seem logical that the 3 d sublevel should be the next lowest in energy. However, the 4 s sublevel is slightly lower in energy than the 3 d sublevel and thus fills first. Following the filling of the 3 d sublevel is the 4 p , then the 5 s and the 4 d . Note that the 4 f sublevel does not fill until just after the 6 s sublevel. The Figure is a useful and simple aid for keeping track of the order of fill of the atomic sublevels.
    ::如图所示,不同主要能源水平的分级能量最终开始重叠。在3p分级之后,3d分级应该是能源中次低的,这似乎是合乎逻辑的。然而,4分级的能量比3d分级略低,因此填充第一。3d分级填充后是4p,然后是5和4d。请注意,4f分级直到6s分级之后才填充。图有助于跟踪原子分级填充顺序。

    Chart showing Aufbau principle order of filling atomic orbitals from low to high energy levels.

    The Aufbau principle is illustrated in the diagram by following each red arrow in order from top to bottom: 1s, 2s, 2p, 3s, etc.
    ::图表中显示Aufbau原则,按从上到下顺序按红箭头顺序排列:1、2、2、2p、3等。

      

     

    Summary
    ::摘要

    • The Aufbau principle gives the order of electron filling in an atom.
      ::Aufbau原则给出了原子电子填充的顺序。
    • It can be used to describe the locations and energy levels of every electron in a given atom.
      ::它可以用来描述特定原子中每个电子的位置和能量水平。

    Review
    ::回顾

    1. What is the Aufbau principle?
      ::Aufbau原则是什么?
    2. Which orbital is filled after the 2 p ?
      ::2点后哪个轨道是填充的?
    3. Which orbital is filled after 4 s ?
      ::4秒后哪个轨道是填充的?
    4. Which orbital is filled after 6 s ?
      ::6秒后哪个轨道是填充的?