纽兰八度定律
元素周期表是一种以表格方式显示元素的方法，其中具有相似品质的元素垂直组合在一起。 Dobereiner 的 Triads 和 Newland 的八度定律是元素分类的早期尝试。当 18 世纪和 19 世纪发现许多新元素时，将元素广泛分为金属和非金属变得无效。进行了几项研究以定位和分组具有可比质量的元素。值得注意的是，早期的元素分类技术，例如纽兰的八度音阶定律和杜伯莱纳的三元组，为当代元素周期表的发展奠定了基础。
杜宾犬的三合会
原子质量是这种分类的基础。据此，当元素按原子质量增加的顺序堆叠时，形成具有可比性质的三种元素的组。三元组中间元素的原子质量几乎等于其他两种元素原子质量的平均值。 Li (6.9)、Na (23) 和 K 只是几个例子 (39)。
纽兰八度定律
一位名叫约翰纽兰兹的英国化学家在 1864 年试图将当时已知的 62 种元素结合起来。他按照原子量升序排列，发现每 8 种元素的性质都是相同的。由于这一发现，纽兰的八度音阶定律诞生了。
The law of octaves states that when the elements are arranged in ascending order of atomic mass, every eighth element has comparable properties.
纽兰兹对比了这些组件与音乐八度音阶的接近程度，其中每个八分音符都与第一个音符相当。这是第一次为每个元素分配原子序数。然而，这种对元素进行分类的方法遭到了科学界的怀疑。
八度法则的例子：
- 钠是锂的八种元素之一。钾、锂、钠、钾是八种钠元素的化学性质。
- 氯是氟之后的第八个元素。氟和氯的化学性质相似。
- 当元素以增加的原子质量顺序排列时，纽兰八度定律表明第八个元素的性质与第一个相同。
纽兰八度法的优点
- 该法律建立了一个框架，用于将具有相似特征的项目分类。
- 该法规赋予政府广泛的权力，可以将所有已知元素组织成表格格式。
- 纽兰八度定律是第一个基于原子量的定律，将元素属性与原子质量联系起来。
- 对于较轻的部分，这种方法的表现要好得多。例如，将锂、钠和钾组合在一起。
纽兰八度定律的局限性
- 在纽兰的周期性分类中，一些元素被组合在一起。镍和钴都放置在同一个槽中。
- 不同的元素质量被组合在一起。例如，钴、镍和铂等金属被归类为卤素。
- 纽兰八度音阶定律只适用于钙含量。具有较高原子质量的元素的原子质量太大而无法容纳在八度音阶内。
- 倍频程布局无法容纳后来发现的组件。结果，使用这种分类方案无法发现新元素。后来发现的元素无法融入八度音阶模式。结果，这种对元素进行分类的方法没有为新元素的发现留下空间。
示例问题
问题 1：为什么将稀有气体放在一个单独的组中？
回答：
Noble gases such as helium (He), neon (Ne), argon (Ar), krypton (Kr), and xenon (Xe) are the most inert (non-reactive) of all known elements and are present in very low concentrations in our atmosphere. As a result, in Mendeleev’s periodic table, they are grouped together in a separate group called zero groups.
问题 2：简要介绍元素的周期性分类历史。
回答：
The periodic table has a history that spans over a century of progress in chemical property understanding. Dmitri Mendeleev published the table in 1869. He based his work on previous discoveries made by scientists such as Antoine-Laurent de Lavoisier and John Newlands.
- The triads of Dobereiner
- The Law of Octaves of Newland
- Periodic Law of Mendeleev
问题 3：Dobereiner 三合会的缺点是什么？
回答：
The drawbacks of Dobereiner’s triads are:
- Dobereiner was only able to identify three triads. He couldn’t make triads of all the known elements.
- All of the known elements could not be arranged in triads.
- The law did not hold true for elements with extremely low or extremely high masses. Consider F, Cl, and Br.
问题四：纽兰八度律有什么好处？
回答：
Advantages of the Newland Law of Octaves are:
- This law establishes a framework for classifying items with comparable features into groups.
- The statute gave the government extensive authority to organise all known elements into a tabular format.
- The Newlands law of octave was the first to be based on atomic weight, linking element properties to atomic masses.
- For the lighter sections, this method performed significantly better. Lithium, sodium, and potassium, for example, were combined.
问题5：什么是门捷列夫元素周期表？他在后来被发现的元素周期表中留下了哪些元素？
回答：
Dmitri Mendeleev, a Russian chemist, published a periodic table in 1869, just five years after John Newlands proposed his Law of Octaves. Mendeleev also arranged the elements known at the time in order of relative atomic mass, but he also did a few other things that contributed to the success of his table. Mendeleev recognized that the physical and chemical properties of elements were ‘periodically’ related to their atomic mass, and arranged them in his table so that groups of elements with similar properties fell into vertical columns.
Germanium, Scandium, and Gallium are the elements discovered but not included in Mendeleev’s periodic table.