Write drawbacks of Mendeleev's erioic table and how they are rectified in modern periodic table ?
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hlo mate here is ur answer .
DRAW BACKS OF MENDELEEFS PERIODIC TABLE :
1. ANOMALOUS PAIR OF ELEMENT : certain elements of highest atomic weight precede those with lower atomic weights.
EXAMPLE :Tellurium ( At .wt. =127.6) preceedes iodine ( at.wt. = 126.9)
2. DISSIMILAR ELEMENTS PLACED TOGETHER : Elements with dissimilar properties were placed in same group as sub-group A and sub -group B.
EXAMPLE : Alkali metals like Li ,Na ,K etc. of 1stA group have little resemblance with coinage metals like Cu,Ag ,Au of 1st B group. 'CL' is of 7th A group and 'Mn' is of 7th B . But chlorine is a non - metal and manganese is a metal .
DRAW BACKS OF MENDELEEFS PERIODIC TABLE :
1. ANOMALOUS PAIR OF ELEMENT : certain elements of highest atomic weight precede those with lower atomic weights.
EXAMPLE :Tellurium ( At .wt. =127.6) preceedes iodine ( at.wt. = 126.9)
2. DISSIMILAR ELEMENTS PLACED TOGETHER : Elements with dissimilar properties were placed in same group as sub-group A and sub -group B.
EXAMPLE : Alkali metals like Li ,Na ,K etc. of 1stA group have little resemblance with coinage metals like Cu,Ag ,Au of 1st B group. 'CL' is of 7th A group and 'Mn' is of 7th B . But chlorine is a non - metal and manganese is a metal .
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