Four elements A, B, C and D form a series of compounds havingthe formulae AB,B_(2), CB_(3), DB_(2)andDB_(3). If the jumbled up atomic numbers of A, B, C and D are 13, 19 , 26 and 35 , What are the ordered atomic numbers of A, BC and C ?

Four elements A, B, C and D form a series of compounds havingthe formu

1.	Four elements A, B, C and D form a series of compounds havingthe formulae AB,B_(2), CB_(3), DB_(2)andDB_(3). If the jumbled up atomic numbers of A, B, C and D are 13, 19 , 26 and 35 , What are the ordered atomic numbers of A, BC and C ?
Answer» Solution :` 13 = Al = 1s^(2) 2s^(2) 2p^(6) 3s^(2) 3p_(x)^(1)` (can lose `1 e ^(-))` ` 19 = K = 1ss^(2) 2s^(2) 2p^(6) 3s^(2) 3p^(6) 4s^(1)(can lose `1e ^(-))` 26 =` Fe= 1s^(2)2s^(2) 2p^(6) 3s^(2) 3p^(6)3d^(6) 4s^(2) `(can lose ` 2e^(-) or 3 r^(-))` 35 ` = Br = 2s^(2) 2s^(2) 3p^(6) 3s^(2)3p^(6) 3d^(10)4s^(2) 4p_(x)^(2) 4p_(y)^(2) 4p_(z)^(1) ` (can gain or SHARE ` 1 e ^(-)` ) Compunds formed will be ` KBR , Br_(2), AlBr_(3), Fe Br_(2) and FeBr_(3).` Hence ,` A = K = 19 , B= Br = 35 , C = Al = 13 , D = Fe = 26.`