The position of three elements A, B and C in the periodic table are shown below: {:("Group 16","Group 17"),(-,-),(-,A),(-,-),(B,C):} (a) State whether A is a metal or non metal. State whether C is more reactive or less reactive than A (c ) Will C be larger or smaller in size than B ? (d) Which type of ion, cation or anion, will be formed by element A?

The position of three elements A, B and C in the periodic table are sh

1.	The position of three elements A, B and C in the periodic table are shown below: {:("Group 16","Group 17"),(-,-),(-,A),(-,-),(B,C):} (a) State whether A is a metal or non metal. State whether C is more reactive or less reactive than A (c ) Will C be larger or smaller in size than B ? (d) Which type of ion, cation or anion, will be formed by element A?
Answer» Solution :(a) Element A is an element of group 17. There are 7 electrons in their valence shell and thus by GAINING ONE more electron it acquire a complete OCTET. Thus, an element A is a non-metal. (b) On going down in a group, the atomic size INCREASES. Therefore, the force of attraction of the nucleus on the incoming electron decreases. As a result, reactivity decreases down the group. Since element C has larger atomic size than A, the element C is less reactive than the element A. In reference of forming positive ion, element C is more reactive than the element A. (c) Elements B and C belong to the same period. On moving left to right in a period, atomic size (volume) decreases. Thus, the atomic size of C is smaller than B. (d) Since element A has 7 electrons in the valence shell, it has a tendency to gain one electron to complete its octet. Thus, element A forms an anion. `A+baretoA^(-)`