AP EAMCET201920 Apr 2019Morning ShiftChemistryClassification of Elements and Periodicity in PropertiesActual
In which of the following the electron gain enthalpy of elements is correctly arranged?
Options
- AS ( > ) Se ( > ) Te ( > O )
- B( F > Cl > Br > 1 )
- C( Na > L > K > Rb )
- D( O > S > Se > Te )
Correct answer
A. S ( > ) Se ( > ) Te ( > O )
Step-by-step solution
On moving down the group electron gain enthalpy decreases. Oxygen due to its small size causes electron-electron repulsions in relatively small (2 p )-subshell. Hence, incoming electrons cannot allow to enter easily, as in case of other elements of this group that's why oxygen has the lowest electron gain enthalpy. Therefore, correct order of electron gain enthalpy, ( S > Se > Te > O . )