In Which year did John Newlands propound the 'Law of Octaves' an innovative concept proposing the periodicity of chemical elements arranged in the order of atomic weight?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 1865.
John Alexander Newlands propounded the concept of the "Law of Octaves" in the year 1865. This law proposed that the chemical elements exhibit similar properties after every eighth element when arranged in order of increasing atomic weight. This concept was later refined by Dmitri Mendeleev who developed the modern periodic table of elements.