The law of triad is applicable to a group of a)`Cl, Br, I` b)C,N,O c)`Na,K,Rb` d)`H,O,N`

Options

A. Cl, Br, I
B. C, N, O
C. Na, K, Rb
D. H, O, N

Answer

A

Explanation

According to the law of triads the atomic wt of the middle element is arithmatic mean of I and III.
At wt of Br = ` ( "At. Wt of "Cl + "At wt of " I ) /( 2 ) `