(Î”GÂ‡) The minimum energy required in order for reacting species to form an activated complex.
( • The energy barrier that blocks the tendency for a set of chemical substances to react.
the minimum amount of energy required to start a reaction; the energy barrier between the reactants and the products
The activation energy is the amount of energy which must be placed into a system before the given chemical reaction will occur. On an energy diagram, this is the difference in energy between the reactants and the transition state. The activation energy is often perceived as an energy barrier which must be overcome for the reaction to proceed.
Distinct states correspond to minima of a potential energy surface in a configuration space. In this classical picture, the activation energy for transforming state A into state B is the maximum increase in energy (relative to the ground state of A) encountered on a minimum-energy path from A to B. Energy here refers to potential energy; an analogous definition based on free energy can be constructed. When tunneling is considered, lower energy paths become possible, but an activation energy can be associated with the reaction (at a given temperature) via the relationship between temperature and reaction rate.
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.
Energy needed to initiate a chemical reaction.
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.
the amount of energy necessary to initiate a chemical reaction. In a cryobiological context, this term refers to the minimum amount of energy required to move water and/or cryoprotectant molecules across a cellular membrane.
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"
The activtion energy is the intial input of energy that allows the reaction to take place.
an energy barrier that must be crossed before chemicals can react.
the kinetic energy (E) which reactant molecules must have before they can take up the transition state and undergo the reaction to form product molecules. Since the transition state is the highest energy state within the reaction, the activation energy is the difference in energy between the enthalpy of the reactants and the enthalpy of the transistion state.
Measure of the sensitivity of a reaction rate to increase in temperature. Activation energy is related to the fundamental energetics of a molecular reaction.
the additional energy which must be supplied for a reaction to occur.
The energy necessary to start a particular reaction.
The input of energy required to (overcome the barrier to) initiate a chemical reaction. By reducing the activation energy, an enzyme increases the rate of a reaction. ( Figure 2-27)
Extra energy that must be possessed by atoms or molecules in addition to their ground-state energy in order to undergo a particular chemical reaction.
The minimum amount of energy which colliding molecules must have before they can react together.
minimum amount of energy, that must be accommodated to a system in order to start a process, mostly for chemical reactions
(Ea) The minimum energy required to convert reactants into products; the difference between the energies of the activated complex and the reactants.
The amount of energy needed to allow a reaction to proceed. (aka energy hump or energy barrier). Needed to form transition structure.
the miminmum energy which reacting species must possess in order to be able to form an 'activated complex', or 'transition state', before proceeding to the products. [The activation energy ( Ea) may be derived from the temperature dependence of the reaction rate using the Arrhenius equation.
The energy required to initiate a chemical reaction or process, abbreviated Ea. For example, a cigarette lighter requires activation energy (provided in the form of a spark) to initiate the reaction of fuel with oxygen.
The energy required to initiate a specific chemical reaction.
This refers to the energy necessary to start a chemical reaction.
In chemistry, activation energy, also called threshold energy, is a term introduced in 1889 by Svante Arrhenius that is defined as the energy that must be overcome in order for a chemical reaction to occur. Activation energy may otherwise be denoted as the minimum energy necessary for a specific chemical reaction to occur. The activation energy of a reaction is usually denoted by Ea.