Identify the molecule for which the enthalpy of atomization ( _ a H ⁻ ) and bond dissociation enthalpy ( _ BOND H ⁻ ) are not equal)

Step-by-step solution

1. For H ₂ - Atomization H ₂ 2 H Bond dissociation H ₂ 2 H so H atomization = H dissociation 2. For Cl ₂ - Atomization Cl ₂ 2 Cl - Bond dissociation Cl ₂ 2 Cl so H _ atom = H _ dissociation 3. For F ₂ Atomization F ₂ 2 ~F Bond dissociation F ₂ 2 ~F so H _ atomization = H _ dissociation 4. CH ₄ Atomization CH ₄ C +4 H Bond dissociation - Each C - H bond in CH ₄ has its own dissociation enthalpy and these are not necessarily the same as enthalpy of atomization. H atomization H dissociation.