Question

what are the achievements of mendeleevs period table what was the basic of classification in it​

Answer 1

Answer:

Mendeleev's table contained all the known elements in order of increasing relative atomic mass.

Answer 2

Answer:

Mendeleev's table contained all the known elements in order of increasing relative atomic mass. Each row contained elements with the same joining power, and he swapped elements to suit this pattern. He left spaces for elements not discovered at the time.