Question

Assertion: The Newland’s law of octaves fails.
Reason: The properties of elements beyond atomic weight 40 cannot be explained.
A.Both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
B. Both Assertion and Reason are correct and Reason is not the correct explanation of Assertion.
C. Assertion is correct but Reason is incorrect.
D. Both Assertion and Reason are incorrect

Answer 1

Hint: Newland’s law of octaves were early attempts for classifying elements into groups based on their properties. Elements till atomic weight of 39, follows a certain trend that eight number elements has the same element as the first element.

Complete step by step solution:
We know that the law of octave states that every element possesses properties that match with the first element when all the elements are placed in the increasing order of the atomic masses. This law states that elements beyond atomic weight 40 do not possess this property that every element possesses properties that match with the first element.
So, Newland's law of octave failed.

Therefore, A is the correct option.

Additional information:
There are various limitations of Newland’s law of octaves. The limitations are:
1)Many elements were able to fit into the same slots in the Newland’s periodic classification, such as cobalt and nickel were placed in the same slot.
2)Elements having dissimilar properties were together grouped, such as the halogens were grouped with some of the metals such as cobalt, nickel, and platinum.
3)Newland’s laws of octaves are true only for elements up to the element calcium. Elements with greater atomic masses than calcium were not able to be fit into octaves.
4)The elements that were later discovered were not being able to fit into the octave pattern.

Note: Newlands compared the elements to the octaves of music, in which every eighth note is comparable to the first. This was the first attempt at assigning an atomic number to each element.