Part (a), this was a popular question among the candidates. Most candidates identified the elements given in the question.
In part (b), some candidates gave the group name wrongly as alkaline instead of alkali metals.  b(i) was well attempted by most candidates.
In part (c), a few candidates mistook the type of bond as covalent bond and therefore give wrong explanation.
In part (d), most candidates could not differentiate between the demands of covalent compound and covalent bond.  Almost all the candidates could not give the factors that affect covalent bonding.  Part d (iii) and (iv) were poorly attempted by most candidates.
The expected responses were:
(a)  (i)   V  and Y
      (ii)  X
      (iii) Z
      (iv) W
      (v)   V and Y
     (vi)   V and Y
     NOTE:  (Do not accept identified elements);

(b)  (i)  -2/2-
      (ii)  alkali metals (Do not accept alkaline metals)

(c)  (i)  V2 W (Do not accept identified elements)
     (ii)  Bond – ionic/electrovalent
            V can readily lose its electrons
            W can readily accept electrons to attain stability

(d)  (i)   A compound formed by two atoms which donate equal number of electrons that
             are shared between them such that each achieves a stable octet.
(ii)-electronegativity (difference)                                                                                                           - ionization energy                                                                                                                            - electron affinity
(iii)  MgO – ionic/electrovalent
        NH3 – covalent
         Fe – metallic
(iv)  = Intermolecular forces are attractive forces that operate between molecules and influence the properties of the substance)