Answer:
The correct answer is option 3.
Step-by-step explanation:
Whenever there is a formation of bond between 2 atoms energy is released. This energy release is due to stability gained by the atoms after the formation of a bond that is why extra energy is released as a heat into surroundings. Exact process is occurring when 2 bromine atoms form bond to give molecule of bromine.
Whenever there is a dissociation of bond between 2 atoms energy is given. The energy provided externally so as to break the stable bond present between the atoms.