A neutron.
activation energy
Potential energy
Activation energy
The energy needed to get a reaction started is called activation energy.
ACTIVATION ENERGY IS THE ENERGY WHICH IS REQUIRED FOR INITIALIZING OF ANY TYPE OF REACTION.
Chemists call the energy needed to get a reaction started the activation energy. This energy is required to break the bonds of the reactant molecules before they can form new bonds and produce products.
enzymes
The amount of energy needed to start a chemical reaction is known as the activation energy. This energy is required to break the existing bonds in the reactants before new bonds can be formed in the products.
If an enzyme is present in lower concentration than the substrates, it may limit the rate of the reaction because there are not enough enzyme molecules available to bind to substrates and catalyze the reaction effectively. This can result in slower reaction kinetics and a decrease in the overall rate of the reaction.
The minimum amount of material needed to sustain a nuclear reaction depends on the type of reaction. For example, in a nuclear fission reaction, a critical mass of fissile material is needed to sustain a chain reaction. In a fusion reaction, high temperatures and pressures are needed to overcome the electrostatic repulsion between nuclei.
a spontaneous reaction
Neutron particle is needed to begin nuclear chain reaction.