* Atomic Size: Bromine is located in the same group (halogens) as fluorine but is in a lower period. Elements in lower periods have more electron shells, leading to a larger atomic size.
* Ionic Charge: Both fluorine and bromine gain one electron to form anions (F⁻ and Br⁻). While the addition of an electron does increase the radius, the increased number of electron shells in bromine outweighs this effect.
In summary: The additional electron shell in bromine makes it significantly larger than fluorine, even after forming anions.
