X belongs to IA or 1^(st) group and 5^(th) period and Y succeeds X in the group. Z succeeds Y in the period. Arrange the following statements in the correct sequence in order to arrange X,Y and Z in the increasing order of their atomic sizes. (1) Effect of number of valence electrons and number of shells on the atomic size. (2) Identification of the elements X,Y and Z. (3) Determination of the number of shells and the number of valence electrons present in X, Y and Z. (4) Determination of the positionns of Y and Z in the periodic table based on the position of X.

X belongs to IA or 1^(st) group and 5^(th) period and Y succeeds X in

1.	X belongs to IA or 1^(st) group and 5^(th) period and Y succeeds X in the group. Z succeeds Y in the period. Arrange the following statements in the correct sequence in order to arrange X,Y and Z in the increasing order of their atomic sizes. (1) Effect of number of valence electrons and number of shells on the atomic size. (2) Identification of the elements X,Y and Z. (3) Determination of the number of shells and the number of valence electrons present in X, Y and Z. (4) Determination of the positionns of Y and Z in the periodic table based on the position of X.
Answer» (a) 4 2 3 1 (b) 2 4 3 1 (c) 3 1 4 (d) 4 3 1 Solution :(1) Determination of the positionns of Y and Z in the PERIODIC table based on the position of X. . (2) Determination of the number of shells and the number of valence electrons present in X, Y and Z. (3) Effect of number of valence electrons and number of shells on the atomic size.