Draw back of Mandel periodic table

1.	Draw back of Mandel periodic table
Answer» 1 - By correct position of isotopes hydrogen 2- By correct position argan And potassium \tHydrogen resembles both the alkali metals and halogens. But it has been placed with the alkalis.\tThe lanthanides and actinides have not been placed in the main body of the table.\tIsotopes discovered long after Mendeléev periodic classification of elements imparted a challenge to Mendeleev’s Periodic Law.

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