Question

What was the basis of the earliest attempts made for classification and grouping of elements?

Answer 1

The basis of earliest attempts for classification of elements was the chemical and physical properties observed by the scientists. Some reactions with known elements and compounds were compared.

The atomic weights were used to order them. To group them into groups they tried to observe the periodicity of the properties as the atomic weight increases.

Law of triads and then the law of octaves was proposed. Doberneiner, Chancourtois and Newlands proposed these laws and prepared some tables.