Answer:
The F¬A¬F bond angles of the AFn species increase in the following order: BeF2 < BF3 < NF3 < OF2 < CF4.
The F¬A¬F bond angle is determined by the electronegativity of the central atom (A) and the size of the surrounding atoms (F). Electronegativity is a measure of an atom's ability to attract electrons, and atoms with high electronegativity tend to have smaller F¬A¬F bond angles. The size of the surrounding atoms also plays a role, as larger atoms result in a wider bond angle.
In the case of the AFn species listed above, the electronegativity of the central atoms increases from beryllium (Be) to nitrogen (N) to oxygen (O) to carbon (C), and the size of the surrounding atoms decreases from fluorine (F) to oxygen (O) to nitrogen (N) to carbon (C). This means that BeF2 has the smallest F¬A¬F bond angle, followed by BF3, NF3, OF2, and finally CF4.