Newland's Octaves
John Alexander Reina Newland was a chemist as well as a lover of music.
He arranged many of the known elements in the increasing order of their atomic masses.
It was noticed that the eighth element was similar in properties to the first element, just like the eighth note in music - Western as well as Indian (Table 8.2).
(i) The law of octaves was the first logical attempt to classify elements on the basis of atomic weights.
(ii) Periodicity of elements was recognised for the first time.
Remember:-
In 1860, there was a conference of chemists in Karl Sruhe, Germany. During this conference, Stanislao Cannizaro, described his method of determining atomic mass of elements.
A young Russian chemist, Dmitri Mendeleev, who was attending the conference, was deeply influenced by Cannizaro's thesis.
He then started working on this aspect of atomic mass and periodicity.
He later on stated the law of chemical periodicity.
| Western | Indian | |
|---|---|---|
| Do | Sa | Lithium, Sodium, Potassium |
| Re | Re | Beryllium, Magnesium, Calcium |
| Me | Ga | Boron, Aluminium |
| Fa | Ma | Carbon, Silicon |
| So | Pa | Nitrogen, Phosphorus |
| La | Da | Oxygen, Sulphur |
| Ti | Ni | Fluorine, Chlorine |
| Do | Sa |
The eighth element after lithium is sodium. It is similar to lithium in many of its chemical properties.
Similarly, the eighth element after sodium is potassium, whose properties are similar to sodium.
The eighth element from fluorine is chlorine both of which are similar in their properties.
The eighth element from nitrogen is phosphorus and both these elements are similar in properties.
Define Octave
Based on this observation, Newland stated his law of octaves thus 'when elements are arranged in increasing order of their atomic mass, the eighth element resembles the first in physical and chemical properties just like the eighth note on a musical scale resembles the first note'. However, a very important conclusion was made that there is some systematic relationship between the order of atomic masses and the repetition of properties of elements.
This gave rise to a new term called periodicity. It is the reccurrence of characteristic properties of elements arranged in a table, at regular intervals of a period.
(i) This law could be best applied, only up to the element calcium.
(ii) Newly discovered elements could not fit into the octave structure.(iii) It failed to exhibit this feature with heavier elements.
