NEETChemistryClassification of Elements and Periodicity in Properties
Why does boron (Z = 5) have a smaller first ionization enthalpy than beryllium (Z = 4)?
Options
- ABoron has fewer electrons.
- BBoron has a smaller nucleus.
- CBoron has a greater nuclear charge.
- DBoron has more shielding electrons.
Correct answer
D. Boron has more shielding electrons.
Step-by-step solution
Boron has a smaller first ionization enthalpy than beryllium because the 2p-electron of boron is more shielded from the nucleus by the inner core of electrons than the 2s electrons of beryllium.