Question

List two criteria mendeleev used in his periodic table to classify the elements

Answer 1

Answer:

Explanation:

1. there are  8 groups in original mendeleev periodic table.These groups are numbered as  1,2,3,4,5,6,7,8(all in roman numerals) .each group from group 1 to 8 are divided into sub groups designated as 1 A and 1 B , 2 A and 2B,.......,8A and 8B.

2.group 8 contains nine elements in three triads.Each triad contain three elements.

(here 1,2,3,4,5,6,7,8=are all in roman numerals)