activation energy

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ac·ti·va·tion energy

The least amount of energy needed for a chemical reaction to occur. For example, striking a match on the side of a matchbox provides the activation energy, in the form of heat, necessary for the chemicals in the match to catch fire.
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Noun1.activation energy - 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"
energy, free energy - (physics) a thermodynamic quantity equivalent to the capacity of a physical system to do work; the units of energy are joules or ergs; "energy can take a wide variety of forms"
aktivacijska energija
References in periodicals archive ?
The coming union of the Disney and Fox media empires is set to create a new nirvana for fanboys and -girls, one that reunites superheroes and sci-fi characters long separated by an energy barrier of corporate legalism.
This class has the ability to deploy an energy barrier that can be used as cover.
It has been found that the energy barrier for the direct cracking of these pyridinic rings is about 600 kJ/mol and that the conversion starts at a temperature of 700 [degrees]C and becomes more intensive at 1200 [degrees]C.
In the paper, lead author Won-Hee Ryu, a former postdoctoral researcher in Taylor's lab, noted that the molecule would dissolve into the battery's electrolytes and act as a redox mediator, which lowers the energy barrier required for the electrochemical reaction to take place.
This kind of addition of electrons usually happens via a quantum-mechanical effect called tunnelling, where electrons tunnel through an energy barrier.
The authors point out that CNT posits local density fluctuations as the cause of critical cluster size and problematically uses the mascroscopic concept of surface tension to determine the energy barrier to nucleation.
The findings were published earlier this year in the Journal of Organic Chemistry, including rearrangement step classifications and a new table listing the energy barrier heights for various steps.
a] with addition of ionic dopant was due to the fact that the increase amount of ions in the polymer electrolytes with concentration leads to the decrease in the energy barrier for the ion transport.
The energy difference between these two points provides the energy barrier for free rotation around the selected bond.
Both, however, require a small additional voltage to overcome the thermodynamic energy barrier for proton reduction into hydrogen gas.
Ordinarily, a chemical reaction occurs only if the reacting molecules have enough energy to overcome a threshold known as the energy barrier, which is like a hill.