Which Kelvin temperatures represent, respectively, the normal freezing point and the normal boiling point of water?
0 K and 273 K
2. OK and 100 K
3 100 K and 273 K
4 273 K and 373K

Which best describes the activation energy of a chemical reaction? a. the combined energy of all the reactants b. the amount of energy required for a reaction to occur c. the difference in energy between products and reactants d. the potential energy stored in the bonds of reactants and products