Final answer:
The elements are ordered from smallest to largest ionic radius by considering both the nuclear charge and the number of electrons. Beryllium ion with the highest positive nuclear charge has the smallest radius, and the nitrogen ion with the smallest charge has the largest radius.
Step-by-step explanation:
To order the elements from smallest to largest ionic radius, we need to consider the number of electrons and the nuclear charge.
As the nuclear charge increases and the electron count remains constant, the ionic radius decreases because the attraction between the nucleus and the electrons becomes stronger, pulling the electrons closer to the nucleus. Therefore, the given ions with 10 electrons each are ordered based on their charges from highest to lowest:
- Beryllium ion (Be 2+)
- Oxygen ion (O2-)
- Fluorine ion (F-)
- Nitrogen ion (N3-)
This order reflects the increasing electrostatic attraction from Be 2+ to N3- and, consequently, the increasing ionic radius.