Question

the modern periodic table has been evolved through the early attempt of dobereiner new land and mendeleev. list one advantage and one limitation of all the three attempts

Answer 1

advantage is there is some one who tries to classify the such a great attempt and gives the courage to classify them
no limits 4 thier think at that time later develop limits bcz of the development that gives more information

Answer 2

Dobreiner introduced law of triads(advantage) his law of triads fail as there were limited elements at the past time(limitation) Newland arranged elements on the basis of musical notes(advantage) after calcium the property of every eighth element does not matches with the first one(limitation) he he had left spaces in his periodic table for the future elements(advantage) position of hydrogen not fixed(limitation)