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  • 量子机械原子能模型

    A masked robber carries a bag of stolen goods, set against a dark background.

    The news flash interrupts your favorite TV program. “There has been a hold-up at the First National Bank. The suspect fled in a car and is believed to be somewhere in the downtown district. Everyone is asked to be on the alert.” The robber can be located only within a certain area – the police do not have an exact location, just a general idea as to the whereabouts of the thief.
    ::新闻闪电打断了你最喜欢的电视节目。 “第一国家银行发生了抢劫事件。 嫌犯乘车逃离,据信在市中心区某处。 所有人都被要求保持警惕。 ”抢劫犯只能集中在某个地区 — — 警方没有确切地点,只是对小偷的下落有一个一般了解。

    Quantum Mechanical Atomic Model
    ::量子机械原子能模型

    In 1926, Austrian physicist Erwin Schrödinger (1887-1961) used the wave-particle duality of the to develop and solve a complex mathematical equation that accurately described the behavior of the electron in a hydrogen . The quantum mechanical model of the atom comes from the solution to Schrödinger’s equation. Quantization of electron energies is a requirement in order to solve the equation. This is unlike the Bohr model, in which quantization was simply assumed with no mathematical basis.
    ::1926年,奥地利物理学家Erwin Schrödinger(1887-1961年)使用波粒二元法来开发和解决一个精确描述氢中电子行为的复杂数学方程式。原子的量子机械模型来自Schrödinger的方程式的解决方案。电能的量子化是解方程式的一个要求。这与Bohr模型不同,该模型只是在没有数学基础的情况下假设了量化。

    Recall that in the Bohr model, the exact path of the electron was restricted to very well-defined circular orbits around the nucleus . The quantum mechanical model is a radical departure from that. Solutions to the Schrödinger wave equation, called wave functions , give only the probability of finding an electron at a given point around the nucleus. Electrons do not travel around the nucleus in simple circular orbits.
    ::回顾在Bohr模型中,电子的确切路径仅限于围绕核的非常明确的圆形轨道。量子机械模型与这个模型截然不同。Schrödinger波方程式的解决方案被称为波函数,它只提供了在核周围某个点找到电子的概率。电子不会在简单的圆形轨道上绕核运行。

    The location of the electrons in the quantum mechanical model of the atom is often referred to as an electron cloud . The electron cloud can be thought of in the following way: Imagine placing a square piece of paper on the floor with a dot in the circle representing the nucleus. Now take a marker and drop it onto the paper repeatedly, making small marks at each point the marker hits. If you drop the marker many, many times, the overall pattern of dots will be roughly circular. If you aim toward the center reasonably well, there will be more dots near the nucleus and progressively fewer dots as you move away from it. Each dot represents a location where the electron could be at any given moment. Because of the uncertainty principle, there is no way to know exactly where the electron is. An electron cloud has variable densities: a high density where the electron is most likely to be and a low density where the electron is least likely to be ( Figure ).
    ::原子量子机械模型中电子的位置通常被称为电子云。电子云可以以以下方式来看待:想象在代表核的圆圈中放置一个圆点的平方纸块。现在,拿一个标记并反复投到纸上,在每个点标记的点击点上留下小标记。如果将标记下落很多次,许多次,圆点的总体模式大致是圆形的。如果瞄准向中点,在向中点移动时会有更多的点,并逐渐减少点。每个点代表一个在任何特定时刻电子可能存在的位置。由于不确定性原理,没有办法知道电子的确切位置。电云有不同的密度:电子最有可能出现的地方是高密度,而电子最不可能出现的地方是低密度(图示 )。

    Diagram illustrating electron cloud density around an atom's nucleus, indicating probability zones.
    An electron cloud: the darker region nearer the nucleus indicates a high probability of finding the electron, while the lighter region further from the nucleus indicates a lower probability of finding the electron.

    In order to specifically define the shape of the cloud, it is customary to refer to the region of space within which there is a 90% probability of finding the electron. This is called an , the three-dimensional region of space that indicates where there is a high probability of finding an electron.
    ::为了具体界定云的形状,通常是指发现电子的概率为90%的空间区域。这称为“三维空间区域”,表明发现电子的概率高。

     

     

     

    Summary
    ::摘要

    • The Schrödinger wave equation replaced the Bohr ideas about electron location with an uncertainty factor.
      ::Schrödinger波波方程式用不确定因素取代了Bohr关于电子位置的想法。
    • The location of the electron can only be given as a probability that the electron is somewhere in a certain area.
      ::电子的位置只能作为电子位于某一区域某处的概率而给出。

    Review
    ::回顾

    1. What does the quantum mechanical view of the atom require?
      ::原子的量子机械视图需要什么?
    2. What is a wave function?
      ::什么是波函数?
    3. What does a high density electron cloud suggest?
      ::高密度电子云意味着什么?