Question

what was the basic classification of elements before the knowledge of electronic structure of atom​

Answer 1

Answer:

only about metal and non metal

Answer 2

ANSWER:

Before the discovery of electronic structure of an atom, elements were classified into three individual groups where each element in a group shared similarities in their properties.

EXPLANATION:  

The accurate electron structure in an atom was made by Bohr in 1923. Before that by 1829, a chemist named Johann Wolfgang classified the elements into based on the similarities in the properties of elements and named them as triads.

In 1864, another proposal for element classification based on the progression of element into 8 groups.