Which of the followingrepresents thecorrectorderof increasingelectrongain enthalpywithnegativesign for aelement O, S , F and C1 ?

Which of the followingrepresents thecorrectorderof increasingelectrong

1.	Which of the followingrepresents thecorrectorderof increasingelectrongain enthalpywithnegativesign for aelement O, S , F and C1 ?
Answer» `S lt O lt C1 lt F` `C1 lt F lt O lt Si` `O lt S lt F lt C1` `F lt S lt O lt Si` SOLUTION :Due togreater electronegativityof halogens over elementsof group 16 the ELECTRON gain enthalpiesof halogens(i.e.,F and C1)are morenegative thanthe correspondingelement ofgroup16 (i.e.,O and S)Furtherdue togreaterinter- electronicrepulsionsin the SMALL size of elementsof 2ndover3rdperiod, the electrongain enthalpiesof elementsof 2ndperiodare lessnegativethan thecorresponding elementsof thethirdperiod.Thusnegative electrongainenthalpiesincrease intheorder : `O(- 141 kJmol^(-1)lt S (- 200 kJmol^(-1))ltF(- 328kJ MOL^(-1)) lt C1(- 349 kJ mol^(-1))` i.e.,option( c) is correct.