$∆{\mathrm{H}}_{\mathrm{atomisation}}=∆{\mathrm{H}}_{\mathrm{Vap}}+\mathrm{Bond} E\mathrm{nergy}$
Hence $\mathrm{x}>\mathrm{y}$

Enthalpy of atomization is enthalpy change involved when one mole of gaseous atom is formed from a substance in an elemental state (Elemental state of Bromine is ${\mathrm{Br}}_2\left(\mathrm{l}\right)$).

While, bond energy is energy required to break one mole of bonds in gaseous state to form separated atoms.