JEE Main202622 January 2026Evening ShiftChemistryd and f Block ElementsActual
Given below are two statements : Statement I : The first ionization enthalpy of Cr is lower than that of Mn . Statement II : The second and third ionization enthalpies of Cr are higher than those of Mn. In the light of the above statements, choose the correct answer from the options given below :
Options
- ABoth Statement I and Statement II are true
- BBoth Statement I and Statement II are false
- CStatement I is false but Statement II is true
- DStatement I is true but Statement II is false
Correct answer
D. Statement I is true but Statement II is false
Step-by-step solution
Statement I: The electronic configuration of Cr is [Ar] 3d^5 4s^1 and Mn is [Ar] 3d^5 4s^2 . For Cr , the first electron is removed from 4s^1 , while for Mn , it is removed from a stable fully filled 4s^2 subshell. Additionally, Mn has a higher nuclear charge. Thus, the first ionization enthalpy ( IE₁ ) of Cr ( 653 kJ/mol ) is lower than that of Mn ( 717 kJ/mol ). Statement I is true. Statement II: For the second ionization enthalpy ( IE₂ ), Cr^+ has configuration [Ar] 3d^5 (stable half-filled) and Mn^+ has [Ar] 3d