(a) Lif and Lif2 (containing theLi+2 ion) Since Li belongs to IA group , looses 1 e- toform Li+ & F belongs to VII A group , accepts 1e- to form F- . ===> Li+ combines with F- to formLiF So the stability of LiF is more. (b) Cs2O and CsO (containing the O-ion) Since Cs belongs to IA group , looses 1e- to form Cs+ & O belongs to VI Agroup , accepts 2e- to form O 2- . ===>2 atoms of Cs+combines with 1 O2- to form Cs2O ==> Cs2O is more stable Since Cs belongs to IA group , looses 1e- to form Cs+ & O belongs to VI Agroup , accepts 2e- to form O 2- . ===>2 atoms of Cs+combines with 1 O2- to form Cs2O ==> Cs2O is more stable (c) CaBr2 and CaBr3 (containingthe Ca3+ ion) Since Ca belongs to IIA group , looses 2e- to form Ca 2+ & Br belongs to VIIA group , accepts 1e- to form Br -. ===>2 atoms of Br - combines with 1 Ca2+ to form CaBr2 ==> CaBr2 is more stable Since Ca belongs to IIA group , looses 2e- to form Ca 2+ & Br belongs to VIIA group , accepts 1e- to form Br -. ===>2 atoms of Br - combines with 1 Ca2+ to form CaBr2 ==> CaBr2 is more stable Solution (a) Lif and Lif2 (containing theLi+2 ion) Since Li belongs to IA group , looses 1 e- toform Li+ & F belongs to VII A group , accepts 1e- to form F- . ===> Li+ combines with F- to formLiF So the stability of LiF is more. (b) Cs2O and CsO (containing the O-ion) Since Cs belongs to IA group , looses 1e- to form Cs+ & O belongs to VI Agroup , accepts 2e- to form O 2- . ===>2 atoms of Cs+combines with 1 O2- to form Cs2O ==> Cs2O is more stable Since Cs belongs to IA group , looses 1e- to form Cs+ & O belongs to VI Agroup , accepts 2e- to form O 2- . ===>2 atoms of Cs+combines with 1 O2- to form Cs2O ==> Cs2O is more stable (c) CaBr2 and CaBr3 (containingthe Ca3+ ion) Since Ca belongs to IIA group , looses 2e- to form Ca 2+ & Br belongs to VIIA group , accepts 1e- to form Br -. ===>2 atoms of Br - combines with 1 Ca2+ to form CaBr2 ==> CaBr2 is more stable Since Ca belongs to IIA group , looses 2e- to form Ca 2+ & Br belongs to VIIA group , accepts 1e- to form Br -. ===>2 atoms of Br - combines with 1 Ca2+ to form CaBr2 ==> CaBr2 is more stable.