Question

At the time of Newlands, how many elements were known?

• A. $50$
• B. $52$
• C. $54$
• D. $56$

Answer 1

The correct option is D $56$

Newlands law of octaves was given by John Alexander Newland in $1865$. He arranged the $56$ elements into octaves. He arranged the elements in increasing order of atomic weights and found that every $8th$ element shows similar properties with the $1st$ element.

Hence, option D is correct.