Which statement about activation energy is true? a. it is not affected by catalysts. b. it has no effect on the rate of the reaction. c. it is the energy required to break existing chemical bonds. d. it is the same for all reactants.

C. the energry required to break existing chemical bonds

1. and 2. question: in which equation? or i don't understand you, 3. a), 4. c), 5. c), 6. b), 7. d), 8. d) if small number is underlined(behind symbol) , b) if big number is underlined(in front of symbol)9. what is underlined there? 10. c)