P 6 2, 4
Q 11 2, 8, 1
R 15 2, 8, 5
S 17 2, 8, 7
Given the above is the electronic arrangement of PQRS elements, Q will form an electrovalent bond with S
Further explanation was provided by our student by name (Odebiyi Dare D-cent) via our facebook page. Thus he says:without argument, D is the answer cos electrovalent involves the transfer of electron. Alreadily, Q is 11 with elect configuratn of 2,8,1, i.e havin 1 valency electron whch is ready to be loss by that atom of element Q, also, S is 17, with ele cnfiguration, with 2,8,7. There the 7valence electron of S attracts that nly 1 electron to attain a stable octet structure.