Question
Fri February 15, 2013 By: Yogiraj Karambelkar
 

Could u please tell how to write an ideal answer of the Mendeleevs' periodic table along with its achievements and demerits.

Expert Reply
Fri February 15, 2013
elements are organised in the Mendeleeves periodic table in the increasing order of their atomic weights.
b.  The the table has 9 vertical columns called groups.
c. six hirizontal rows callled series or periods.
 
ACHIEVEMENTS.
a. systematic stydy of elements.
b. Prediction of new elements.
c. correction of doubtful atomic weights.
 
DEMERITS.
a. Anomalous position of hydrogen.(group IA or VII A)
b. Anomalous pairs of elements - some elements with higher atomic weights preecede the ones with lower weights.
c. position of isotopes.
d. dissimilar elements are grouped together.
e. 
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