The energy required to initiate a reaction. For example, the flame from the fuse of a firecracker provides a small initial amount of energy, after which the explosive reaction proceeds by itself, releasing a considerably larger quantity of energy. A small push given to a stable but top-heavy object may cause it to fall over; the potential energy released during the fall was present in the system all along but could not be realized as long as the object was upright and balanced
the energy that an atomic system must acquire before a process (such as an emission or reaction) can occur; "catalysts are said to reduce the energy of activation during the transition phase of a reaction
A term used in kinetics to indicate the amount of energy required to bring all molecules in one mole of a substance to their reactive state at a given temperature Conceptually, this energy barrier must be overcome to get a reaction to go forward At higher activation energies, reactions are slower if temperature and composition are constant It is usually determined from an Arrhenius plot of the inverse of the absolute temperature vs rates of reaction at different temperatures
The difference in energy between the ground state and transition state The amount of activation energy required by a reaction determines the rate at which the reaction proceeds Most reactions have activation energies of 40-100 kJ/mol
An amount of energy required by colliding molecules to complete a chemical reaction
minimum amount of energy needed for reaction to occurCatalyst: chemical added to a system to lower the activation energy and speed up the reaction (Heterogeneous: catalyst is in a different phase than reactants; Homogeneous: catalyst is in the same phase as reactants, i e both liquids)
for the forward reaction is the energy required to go from reactants to the transition state The activation energy for the reverse reaction is the energy required to go from products to the transition state
In a chemical reaction, the energy that must be added to the reactants in order to allow a reaction to occur See Arrhenius equation, preexponential factor
(Ea) - The energy level that must be overcome by the reactants in a chemical reaction in order for the reaction to occur
The energy that must be provided to the reactants in a chemical reaction to reach an intermediate or activated state from which the products of the reaction can form
Measure of the sensitivity of a reaction rate to increase in temperature Activation energy is related to the fundamental energetics of a molecular reaction
Minimum amount of energy (heat, electromagnetic radiation, or electrical energy) required to activate atoms or molecules to a condition in which it is equally likely that they will undergo chemical reaction or transport as it is that they will return to their original state. Chemists posit a transition state between the initial conditions and the product conditions and theorize that the activation energy is the amount of energy required to boost the initial materials "uphill" to the transition state; the reaction then proceeds "downhill" to form the product materials. Catalysts (including enzymes) lower the activation energy by altering the transition state. Activation energies are determined by experiments that measure them as the constant of proportionality in the equation describing the dependence of reaction rate on temperature, proposed by Svante Arrhenius. See also entropy, heat of reaction
the energy required to make a collision (of molecules) sufficient enough to form the transition state
The amount of energy needed to allow a reaction to proceed (aka energy hump or energy barrier) Needed to form transition structure