Question

AN ANYONE GIVE ME ALL DRAWBACKS AND CONTRIBUTION OF DOBEREIGNER , NEWLAND AND MENDELEEV . I WILL MARK BRAINLIEST PLUS GIVE ALL MY POINTS . BUT I NEED BOTH DRAWBACKS AND CONTRIBUTION OF ALL PERSONS ..

Answer 1

In 1896 Dobereiner stated that if we would arrange elements on the basis of increasing atomic mass there is repitition of properties after every eight elements. . But as we know isotopes have different atomic mass so according to Dobereiner concept they should have diiferent properties and also occup more space. . And now numerous different isotopes occur but all have similar properties to similar elements. . So attempts continued to solve this problem, then in 1913 Moseley gave concept of atomic number which means if elements are arranged on the basis of atomic numbers we not need to write isotopes and it saves periodic table to be long. .

Answer 2

Here is my answer

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