Question

difference between dobereiner table, Newlands table and Mandeleeve's table????

Answer 1

difference between dobereiner table, Newlands table and Mandeleeve's table are
dobereiner table
1) the atomic mass of the middle element being equal to the airthmetic mean of the atomic masses of other two element
2) elements were arranged in increasing atomic masses, the group of three elements were known as triads having similar chemical properties.
NEW Land
1)he has put two unlike elements having different properties in one slot
2)iron which resembles cobalt and nickel element in properties was placed far away from these elements
MANDALEEV
1)when elements are arranged in increasing atomic masses the elements with similar chemical properties occur at regular intervals
2)wrong order of atomic masses of some elements