CBSE Class 10 Chemistry Classification Early Attempts


What should be the atomic mass of the middle element of a Dobereiner's triad if the other two elements have atomic masses 7 and 39? 


The unknown element of Mendeleev's periodic table eka-boron was later named  


Which element was not predicted by Mendeleev before its discovery?

Periodic Classification of Elements - Exam Decoded - 1

Study of early attempts of classification, Mendeleev's periodic table-Achievements and limitations

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