Question
Sun February 20, 2011 By: Akriti None
its a 5 mark q maam!!!

urgent

Expert Reply
Sun February 20, 2011

Dear student

Groups are vertical columns while periods are horizontal rows

Group 1,2 and 13 to 18 elements are called representative elements. In these elements the ultimate shell is incompletely filled

Group 3 to 12 are called transition elements

For your boards only learn first 20 elements

Please post ur querries separately

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