Question

which of the following isoelectronic species has the smallest atomic radius:
a. F-
b. O2-
c. N3-
d. Ne​

Answer 1

The correct answer to this question is option a. F-.

Step-by-step explanation:

• Fluorine is the most electronegative element as it has 5 electrons in its 2P sub-shell.  

• The ideal electron configuration of the 2P orbital is of 6 electrons, and since F- has this ideal electron configuration, the electrons are held very tightly to the nucleus.

• The high electronegativity of F- explains its small radius as the positive protons impart a very strong attraction to the negative electrons, holding them very close to the nucleus than the larger and less electronegative elements.