(i) Type of bond formed
(a) W (2,8,1) and X (2,8,7) — Electrovalent bond is formed as W donates 1 electron and X takes up that electron and both attain a stable octet.
(b) Y (2, 5) and Z (1) — Covalent bond as electron sharing takes place between the two elements. The valency of Z element is 1 and that of Y is 3. Z needs one electrons to attain stable duplet structure of nearest noble gas – He [2] and Y needs three electrons to attain stable octet structure of nearest noble gas – Ne [2,8]
One Y atom shares three electron pairs one with each of the three atoms of Z such that Z acquires a duplet configuration and Y attain a stable octet configuration resulting in the formation of three single covalent bonds.
(ii) Formula of the compound formed
(a) X (2,8,7) and Z (1) — XZ as X needs one 1 electron to complete it’s octet and Z needs needs one electron to complete it’s duplet hence, they both share one electron pair and forms ZX compound.
(b) W (2,8,1) and X (2,8,7) — WX as W has the tendency to donate one electron and gain stability whereas X has the tendency to gain one electron to be stable. Hence, W donates one electron and X takes it and form WX compound.