Newlands law of Octaves was applicable only up to element _______.

Correct option is D

The correct answer is (d) Ca (Calcium).

Explanation:

Newlands' Law of Octaves was a theory proposed by John Newlands in 1864. Newlands suggested that when elements were arranged in order of their atomic masses, the properties of every eighth element were similar, much like how the eighth note in a musical scale repeats the properties of the first note.

Key points about Newlands' Law of Octaves:

• Newlands noticed that elements, when arranged in order of increasing atomic masses, exhibited a repeating pattern in their chemical properties every eight elements.
• For example, the first eight elements (H, He, Li, Be, B, C, N, O) seemed to follow this pattern where properties of the first element (H) were similar to the eighth element (O), the second (He) with the ninth (F), and so on.

Limitations of Newlands' Law of Octaves:

• After calcium (Ca), the law failed to work effectively.
• Newlands was only able to arrange the first 20 elements using the Law of Octaves.
• Beyond calcium (Ca), the periodicity of elements did not match up as expected, especially with the heavier elements like scandium, titanium, and others.

• Calcium (Ca) is the last element that fits well with Newlands' Law of Octaves.
• Beyond calcium, the properties of the elements did not repeat in a pattern that could be explained by the law. For example, scandium (Sc), the next element, did not share similar properties with calcium, disrupting the octaval pattern.