Amount of energy needed to weaken the existing bonds to an extent that can be broken through collision is called:

Explanation

Activation energy is the barrier reactant molecules must climb to reach the transition state, and only collisions carrying at least this much energy, with the right orientation, lead to reaction. Bond energy is the energy needed to break a particular bond completely in the gaseous state, a different quantity. A catalyst works by lowering the activation energy, not the bond energy.