Newland's Law of Octaves also called Law of Octaves was one of the initial attempts to arrange all the known chemical elements in a table to make their study better. In Newland's Law of Octaves, elements are arranged in the increasing order of their atomic mass and it is seen that the property of the Eight elements starting from any element resembles the starting elements. This is similar to the Law of Octaves in music in which the eight nodes in music in which any node is always similar to its eight nodes. Thus, the name Newland's Law of Octaves.
In this article, will learn about Newland's Law of Octaves, Examples of Newland's Law of Octaves, Advantages and Limitations of Newland's Law of Octaves in detail.
Table of Content
What is Newland's Law of Octaves?
A British chemist named John Newlands attempted to combine the 62 elements known at the time in 1864. He arranged them in ascending order according to their atomic weights and discovered that the properties of every eighth element were the same. As a result of this discovery, Newland's law of Octaves was born.
The law of octaves states that when the elements are arranged in ascending order of atomic mass, every eighth element has similar properties.
Check: Classification of Elements
Example of Newland's Octaves
The image added below shows the Newland's Octaves
- Sodium is eighth element following Lithium. Lithium, Sodium, and Potassium have similar chemical properties.
- Chlorine is the eighth element after Fluorine. The chemical properties of Fluorine and Chlorine are similar.
Advantages of Newland's Law of Octaves
Various advantages of Newland's Law of Octaves are,
- This law establishes a framework for classifying items with comparable features into groups.
- Newland's law of octave was the first to be based on atomic weight, linking element properties to atomic masses.
- For the lighter elements, this method performed significantly better. Lithium, Sodium, and Potassium, for example, were combined.
Check: History of Periodic Table
Limitations of Newland’s Law of Octaves
Various limitations faced by Newland's Law of Octaves were,
- In Newland's periodic classification, some elements that are not similar were grouped together. Nickel and Cobalt were both placed in the same slot.
- Element qualities that were distinct were grouped together. Metals such as cobalt, nickel, and platinum, for example, were classified as halogens.
- Newland's Law of Octaves hold true up to Calcium. Elements with higher atomic masses had atomic masses that were too large to fit within octaves.
- The octave layout was unable to accommodate later discovered components. As a result, new elements could not be discovered using this classification scheme.
In the same time when Newland's was busy in arranging elements on the basis of their atomic mass in the form of Octaves, Dobereiner another famous chemist of that time was also busy in arranging and grouping elements together. He proposed a concept called Doberiner's Triads that is explained below.
Dobereiner’s Triads
Prior to Newland, Dobereiner’s was the first to make an attempt to arrange the atoms in a table based on their common properties. He arranged three atoms in a column and such columns were called Triads.
Doberenier's Triads uses atomic mass as the basis for classification. According to this, groups of three elements with comparable properties are formed when elements are stacked in order of increasing atomic masses. The atomic mass of the triad's middle element is almost equal to the average of the other two elements' atomic masses. Li (6.9), Na (23), and K are only a few examples (39).
Check: Anomalies of Mendeleev’s Periodic Table
Limitations of Dobereiner’s Triads
Limited applicability: Dobereiner's Triads worked only for a few groups of elements, leaving out many others.
Arbitrary selection: The triads were based on the choice of three elements with similar chemical properties, making the selection somewhat subjective.
Inconsistent patterns: Not all elements could be grouped into triads, and some triads displayed inconsistencies in chemical properties.
Ignored isotopes: Dobereiner's Triads did not account for isotopes, which have the same chemical properties but different atomic masses.
Limited predictive power: While the triads identified patterns among known elements, they lacked the predictive power to anticipate the properties of undiscovered elements.
Superseded by modern periodic table: The advent of Mendeleev's periodic table, which organized elements by atomic number and grouped them based on similar properties, rendered Döbereiner's Triads obsolete.
Also, Check