My apologies, I don’t seem to understand the question.
In general terms, exothermic reactions release energy, so the energy goes from the system to the surroundings.
When two atoms of Florine combines, they share an electron pair to complete it's octet. This result is formation of single bond between two fluorine atoms. This process is exothermic in nature, and hence, heat is liberated during the process of bond formation. <span />
