Question

write about newlands classification and their defects​

Answer 1

Law of octaves, in chemistry, the generalization made by the English chemist J.A.R. Newlands in 1865 that, if the chemical elements are arranged according to increasing atomic weight, those with similar physical and chemical properties occur after each interval of seven elements.

Drawbacks of Newlands Law of Octaves

Out of the total 56 known elements, Newland could arrange elements only up to calcium. Every eighth element did not show properties similar to that of the first after calcium. Just 56 elements were known at the time of Newlands, but afterwards, various elements were discovered.