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.
1 5 1
The English chemist Newlands formulated the Law of Octaves in 1865. He found that when he arranged the elements on the basis of their atomic mass. Then the chemical properties of the 8th element are similar to the 1st element and hence repeat after the 7th element. 

Thank you.....!!!!
Mark as brainliest of helpful..
Yours, Jahnavi.