State the group and period of the element having three shells with three electrons in the valence shell.

The electron affinity of an element X is greater than that of element Y.

(a) How is the oxidising power of X likely to compare with that of Y?

(b) How is the electronegativity of X likely to compare with that of Y?

(c) State whether X is likely to be placed to the left or to the right of Y in the periodic table?

Arrange the following in order of :

(i) increasing radii.

(a) Cl^-, Cl
(b) Mg²⁺, Mg, Mg⁺
(c) N, O, P

(ii) increasing ionisation energy.

(a) P, Na, Cl
(b) F, O, Ne
(c) Ne, He, Ar

Explain your choice.

Atomic numbers of elements A, B, C, D, E, F, are 8, 7, 11, 12, 13 and 9 respectively. State the type of ions they form.