《定期法》

How are these items related to one another?
::这些项目之间如何相互关联?

We have all enjoyed looking around a market for delicious foods to eat later at home. When you get to the market you know you need to get fruits, vegetables and grains to ensure you eat a balanced diet. In the market, these items are all grouped together to make it easier to find the type of fruit, vegetable or grain you are looking for; it would be inconvenient if the different fruits were all scattered in different places. The periodic table is organized in a similar way, ensuring similar are found in the same group or period.
::我们都喜欢在市场周围寻找美味食品,然后在家里吃饭。当你来到市场时,你知道你需要得到水果、蔬菜和谷物,以确保你吃均衡的饮食。在市场中,这些物品都组合在一起,以便更容易地找到你所寻找的水果、蔬菜或谷物的类型;如果不同的水果分散在不同的地方,则会很不方便。定期会议以类似的方式安排,确保在同一组或同一期间也能找到类似的水果、蔬菜或谷物。

The Periodic Law  
::《定期法》

When Mendeleev put his periodic table together, nobody knew about the existence of the nucleus .  It was not until 1911 that Rutherford conducted his that demonstrated the presence of the nucleus in the . Just two years later, in 1913, English physicist Henry Moseley (1887-1915) examined x-ray spectra of a number of chemical elements. He would shoot X-rays through crystals of the element and study the wavelengths of the radiation he detected.  Moseley found that there was a relationship between wavelength and . His results led to the definition of atomic number as the number of contained in the nucleus of each atom. He then realized that the elements of the periodic table should be arranged in order of increasing atomic number rather than increasing atomic mass .
::当Mendeleev把周期表放在一起时,没有人知道核的存在。直到1911年,卢瑟福德才进行显示核的存在。就在两年后,1913年,英国物理学家亨利·莫塞利(1887-1915年)检查了许多化学元素的X射线光谱。他将通过元素的晶体拍摄X射线并研究他检测到的辐射波长。摩斯利发现波长和原子波长之间存在某种关系。他的结果导致将原子数定义为每个原子核中所含原子数。他随后意识到周期表的元素应该按照增加原子数而不是增加原子质量来排列。

When ordered by atomic number, the discrepancies within Mendeleev’s table disappeared. Tellurium has an atomic number of 52, while iodine has an atomic number of 53. So even though tellurium does indeed have a greater atomic mass than iodine, it is properly placed before iodine in the periodic table. Mendeleev and Moseley are credited with being most responsible for the modern periodic law : When elements are arranged in order of increasing atomic number, there is a periodic repetition of their chemical and . The result is the periodic table as we know it today. Each new horizontal row of the periodic table corresponds to the beginning of a new period because a new principal energy level is being filled with electrons. Elements with similar chemical properties appear at regular intervals, within the vertical columns called groups .
::当按原子数排列时,门捷列夫的表内差异就会消失。 的原子数为52,而碘的原子数为53。 因此,尽管的原子质量确实比碘大,但它还是被恰当地置于碘的周期表前。 门捷列夫和莫斯利被认为对现代周期法负有最大责任:当元素按原子数增加顺序排列时,它们的化学成分会定期重复。 结果是我们所知道的周期表。 周期表的每条新的水平行都与新时期的开始相对应,因为新的主要能量水平正在被电填满。 类似化学特性的元素会定期出现在垂直列中, 被称为“ 组 组 ” 。

Summary  
::摘要

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• Elements of the periodic table are arranged in order of increasing atomic number.
  ::定期表格各部分按原子数的增加顺序排列。
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• The periodic law states “When elements are arranged in order of increasing atomic number, there is a periodic repetition of their chemical and physical properties.”
  ::定期法律规定,“当元素按照增加原子数量排列时,其化学和物理特性会定期重复。”

Review
::回顾

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1. Did Mendeleev know about the nucleus of an atom?
   ::Mendeleev知道原子的核心吗?
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2. Who discovered the relationship between wavelength of X-rays and atomic number?
   ::谁发现了X光波长与原子数之间的关系?
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3. What did Moseley conclude from his research?
   ::Moseley从他的研究中得出了什么结论?
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4. What is the “periodic law”?
   ::“定期法”是什么?
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5. What do the vertical columns (groups) in the periodic table represent?
   ::周期表中的垂直列(组)代表什么?