The energy needed to destabilize existing chemical bonds and start a chemical reaction is called:

• A. enthalpy
• B. activation energy
• C. free energy
• D. bond energy

Answer: (B)

Verified step by step guidance

1. Understand the key terms related to energy in chemical reactions: enthalpy, activation energy, free energy, and bond energy.
2. Recall that enthalpy (\$\Delta H\$) refers to the heat content or heat absorbed/released during a reaction, not the initial energy needed to start it.
3. Recognize that free energy (\$\Delta G\$) indicates the spontaneity of a reaction, combining enthalpy and entropy effects, but it is not specifically the energy to initiate the reaction.
4. Know that bond energy is the energy required to break a specific chemical bond, but the term for the overall energy barrier to start a reaction is different.
5. Identify that the energy needed to destabilize existing bonds and initiate a chemical reaction is called the activation energy, which represents the minimum energy required to reach the transition state.