Thank you so much! Can i clarify why did you add the -3 infront of the B.E (Br-F) for the energy cycle ? Because i didn’t add it in ..

So sorry for the late reply! Hopefully it wasn't your A lvl year!

To clarify, Bond energy is always defined as the energy required to break a bond (positive; exothermic) i.e. from compound to constituent - in the diagram i drew, I standardised the arrows to all go in one direct from bromine and fluorine in standard states, to gaseous bromine fluoride. Therefore since I'm going from gaseous atoms to the compound, this is a formation of bonds = negative bond energy = negative values.