Whichof the followingwill havethe mostnegativeelectrongainenthalpyand whichthe leastnegative? P, S, Cl, F Explainyouranswer.

Whichof the followingwill havethe mostnegativeelectrongainenthalpyand

1.	Whichof the followingwill havethe mostnegativeelectrongainenthalpyand whichthe leastnegative? P, S, Cl, F Explainyouranswer.
Answer» Solution :Arrangingthe givenatomsintodifferent groupsandperiodsin orderof increasingatomicnumbers Aswe moreacrossa periodfromleftto rightthe electrongain enthalpybecomesmore andmorenegative while withthe groupfrom top tobottom it BECOMES lessand less NEGATIVE. Therefore , Fshouldhave themostnegativeelectrongainenthalpywhile Pshouldhave theleastnegativeelectron gain enthalpy. Butaddingan electron to LARGER 3P- orbitall of CI.HenceCl has themostnegativeelectron gainenthalpywhile PHAS thelest negativeelectron gainenthalpy .