Answer is: Both a fluorine atom and a bromine atom gain one electron, and both atoms become stable.
Fluorine and bromine are in group 17 in Periodic table of elements. Group 17 (halogens) elements are in group 17: fluorine (F), chlorine (Cl), bromine (Br) and iodine (I). They are very reactive and easily form many compounds.
Halogens need to gain one electron to have electron cofiguration like next to it noble gas.
Fluorine has atomic number 9, it means it has 9 protons and 9 electrons.
Fluorine tends to have eight electrons in outer shell like neon (noble gas) and gains one electron in chemical reaction.
Electron configuration of fluorine: ₉F 1s² 2s² 2p⁵.
Electron configuration of neon: ₁₀Ne 1s² 2s² 2p⁶.
Explanation:
Both fluorine and chlorine are non-metals and since they belong to the same group that means they have same number of valence electrons.
That is, fluorine and chlorine has 7 valence electrons. So, in order to complete their octet they need one electron. Hence, they will readily react.
For example, Br will readily react with sodium (Na) atom and results in the formation of NaBr.
[tex]Br^{-} + Na^{+} \rightarrow NaBr[/tex]
