Newlands Law Of Octaves

In 1866, John Newlands, an English scientist, arranged the known elements in an increasing order of their atomic masses.

He began with hydrogen, which has the lowest atomic mass. He observed that if the elements are arranged in the increasing order of their atomic masses, then every eighth element (starting from a given element) had properties similar to those of the first element. Therefore, he arranged the elements in seven groups such that elements having same properties were present below each other in the form of a group (shown in table). He arranged 56 elements in his table.

Newlands Octaves

He compared his table to the octaves of music. It is for this reason that he called his model the Law of Octaves or Newlands Law of Octaves.

DO YOU KNOW?

There are seven musical notes in the Indian system of music. They are - sa, re, ga, ma, pa, da, ni. Similarly, in the west, they use the notations - do, re, mi, fa, so, la, ti. Every eighth note is similar to the first one and it is the first note of the next scale.

According to Newlands Law of Octaves, the properties of fluorine (eighth element starting from hydrogen) are similar to those of hydrogen. Similarly, the properties of sodium are similar to those of lithium; the properties of magnesium are similar to those of beryllium; and so on.

Newland’s arrangement of atoms showed for the first time that elements could be arranged and grouped based on some fundamental property such as the atomic mass.

Do you know that Newlands Law of Octaves was found applicable only for the elements having low atomic masses?

Newlands Law of Octaves has many limitations, which are discussed below.

• This law was not applicable throughout the arrangement. It was applicable only till calcium.

• Newlands assumed that only 56 elements would exist in nature and believed that no more elements would be discovered. However, several elements were discovered in the following years. These elements did not follow the Law of Octaves.

• The positions of cobalt and nickel could not be explained according to Newlands Law of Octaves. He kept cobalt and nickel in the same slot. They were also placed in the same column as fluorine and chlorine, which have completely different properties.

• The properties of iron are similar to those of cobalt and nickel. However, iron was placed away from them in a different column.

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