COMEDK2023Morning ShiftChemistryClassification of Elements and Periodicity in PropertiesActual
The correct decreasing order of negative electron gain enthalpy for C , Ca , Al , F and O is
Options
- AF > C > O > Ca > Al
- BAl > F > Ca > C > O
- CF > O > C > Al > Ca
- DCa > Al > O > F > C
Correct answer
C. F > O > C > Al > Ca
Step-by-step solution
The electron gain enthalpy is the energy released when an electron is added to a neutral gaseous atom. Generally, it becomes more negative (higher magnitude) across a period from left to right and decreases down a group. The elements given are F (Group 17, Period 2), O (Group 16, Period 2), C (Group 14, Period 2), Al (Group 13, Period 3), and Ca (Group 2, Period 4). Comparing the magnitudes of electron gain enthalpy: 1. F has the highest negative electron gain enthalpy among these due to its small size and high eff