- Exam
- JEE Main
- Year
- 2022
- Date
- 27 July
- Shift
- Morning Shift
- Subject
- Chemistry
- Chapter
- Classification of Elements and Periodicity in Properties
JEE Main 2022 · 27 July · Morning Shift · Chemistry · Classification of Elements and Periodicity in Properties
The incorrect statement is
Options
- AThe first ionization enthalpy of is less than that of and
- B does not have the lowest first ionization enthalpy in its group
- CThe first ionization enthalpy of element with atomic number is lower than that of the element with atomic number .
- DThe first ionization enthalpy of is higher than that of the d-block element with atomic number .
Correct answer
D. The first ionization enthalpy of is higher than that of the d-block element with atomic number .
Step-by-step solution
Ionisation enthalpy of alkali metals decreases down the group from Li to Cs. This is because of increase in size which outweighs the increasing nuclear charge, and the outermost electron is very well screened from the nuclear charge.
Due to stable electronic configuration noble gases exhibit very high ionisation enthalpy. However, it decreases down the group with increase in atomic size.
Alkaline earths have higher ionization enthalpy values than alkali metals. This is because the atomic size of alkaline earths is smaller than that of alkali metals.
Because of completely filled configuration, zinc is stable and requires higher ionization energy whereas gallium is yet to fill its p-orbitals, so it has lower ionization energy compared to zinc.