Question

The morden periodic table has been evolved through the early attempts of dobereiner , newland andendeleev, list one advantage and one limitation of all the three attemps

Answer 1

Advantage of dobereiner :

He had thought to arrange elements in a particular way

Disadvantage :

He could only find 3 triads

Advantage of newland :

He provided a basis for classifying elements on having similar properties

Disadvantage:

His rule of octaves existed only upto 20 elements

Advantage of mendeleev:

He gave separate places to noble gases and he could say the properties of elements not yet discovered

Disadvantage :

He could not provide a position for hydrogen and no explanation for the positions of isotopes.

All the 3 attempts were found out to be wrong but they helped a lot in the formation of the modern periodic table