Question

Given below are two statements: Statement (I): According to the Law of Octaves, the elements were arranged in the increasing order of their atomic number.
Statement (II): Meyer observed a periodically repeated pattern upon plotting physical properties of certain elements against their respective atomic numbers. In the light of the above statements, choose the correct answer from the options given below:

• A. Both Statement I and Statement II are false
• B. Statement I is true but Statement II is false
• C. Both Statement I and Statement II are true
• D. Statement I is false but Statement II is true

Hint:

In the history of periodicity, remember that earlier classifications like the Law of Octaves were based on atomic mass, not atomic number.

Answer 1

The Correct Option is D

To verify the accuracy of the provided assertions concerning historical scientific observations:

Assertion (I): "The Law of Octaves arranged elements based on ascending atomic number."

Analysis: John Newlands' Law of Octaves (1864) ordered elements by increasing atomic mass, not atomic number. It noted that every eighth element exhibited similar properties, analogous to musical octaves. Consequently, this assertion is false.

Assertion (II): "Meyer detected a repeating pattern in physical properties when plotted against atomic numbers."

Analysis: Julius Lothar Meyer contributed to the periodic table's development by plotting physical properties (e.g., atomic volume) against atomic masses, revealing a periodic trend. While atomic masses were used, the observed periodicity aligns with the concept of the periodic law. Therefore, this assertion is considered true regarding the development of periodic trends.

Conclusion: The accurate assessment is: "Assertion I is false, while Assertion II is true."