New atoms are also naturally produced on Earth as radiogenic daughter isotopes of ongoing radioactive decay processes such as alpha decay, beta decay, spontaneous fission, cluster decay, and other rarer modes of decay.

The reaction was repeated in 1994 and the team were able to measure both alpha decay and spontaneous fission for < sup > 264 </ sup > Hs.

Using the rotating drum technique, they were able to detect a spontaneous fission activity assigned to < sup > 255 </ sup > Rf, descendant of the < sup > 263 </ sup > Hs decay chain.

Two classes of mutations are spontaneous mutations ( molecular decay ) and induced mutations caused by mutagens.

The process of alpha decay is in essence a special type of spontaneous nuclear fission.

Heavy nuclei such as uranium and thorium may undergo spontaneous fission, but they are much more likely to undergo decay by alpha decay.

It is less commonly encountered as a natural form of spontaneous radioactive decay ( not requiring a neutron ), occurring especially in very high-mass-number isotopes.

Nuclear reactions are thus driven by the mechanics of bombardment, not by the relatively constant exponential decay and half-life characteristic of spontaneous radioactive processes.

Most nuclear fuels undergo spontaneous fission only very slowly, decaying instead mainly via an alpha / beta decay chain over periods of millennia to eons.

Several heavy elements, such as uranium, thorium, and plutonium, undergo both spontaneous fission, a form of radioactive decay and induced fission, a form of nuclear reaction.

If a collection of atoms are in the excited state, spontaneous decay events to the ground state will occur at a rate proportional to N < sub > 2 </ sub >, the number of atoms in the excited state.

Some of these atoms decay via spontaneous emission, releasing incoherent light as photons of frequency, ν.

An atom in level 2 may decay by spontaneous emission to the ground state, releasing a photon of frequency ν < sub > 12 </ sub > ( given by E < sub > 2 </ sub > – E < sub > 1 </ sub > = hν < sub > 12 </ sub >), which is shown as the transition L, called the laser transition in the diagram.

These estimates predict that a large volume of material will occasionally exhibit a spontaneous proton decay.

The measurement of a spontaneous fission activity was assigned to < sup > 256 </ sup > Rf ,< ref > while later studies done at the Gesellschaft für Schwerionenforschung Institute ( GSI ), also measured decay properties for the isotopes < sup > 257 </ sup > Rf, and < sup > 255 </ sup > Rf .< ref >< ref name = 97He01 >

The final decay product, lead-208 (< sup > 208 </ sup > Pb ), is stable and can no longer undergo spontaneous radioactive decay.

This transformation may be accomplished in a number of different ways, including radioactive decay, either by emission of particles ( usually electrons ( beta decay ), positrons or alpha particles ) or by spontaneous fission, and electron capture.

Since one must consider probabilities that occupy all of phase space equally, the combined system of atom plus electromagnetic field must undergo a transition from electronic excitation to a photonic excitation ; the atom must decay by spontaneous emission.

Observers can see a person engaged in spontaneous behavior, and watch him operating in a totalistic fashion.

The necessity for keeping alert to his bride's hazards can act as an interference with the man's spontaneous desire.

In theory it can occur only in nuclei somewhat heavier than nickel ( element 28 ), where overall binding energy per nucleon is no longer a minimum, and the nuclides are therefore unstable toward spontaneous fission-type processes.

While a spontaneous or induced genetic mutation in bacteria may confer resistance to antimicrobial drugs, genes that confer resistance can be transferred between bacteria in a horizontal fashion by conjugation, transduction, or transformation.

In a woman, the condition of lactation unrelated to pregnancy can occur as galactorrhea ( spontaneous milk flow ), and because of the adverse effects of drugs ( e. g. antipsychotic medications ), of extreme physical stress, and of endocrine disorders.

Chlamydia can affect infants by causing spontaneous abortion ; premature birth ; conjunctivitis, which may lead to blindness ; and pneumonia.

A spontaneous electrochemical reaction ( change in Gibbs free energy less than zero ) can be used to generate an electric current in electrochemical cells.

Other precipitants can trigger an epileptic seizure in patients who otherwise would be susceptible to spontaneous seizures.

* The juerga is an informal, spontaneous gathering, rather like a jazz " jam session ", that can include dancing, singing, palmas ( hand clapping ), or simply pounding in rhythm on an orange crate or table, adapting to local talent, instrumentation and mood.

When the temperature rises beyond a certain point, called the Curie temperature, there is a second-order phase transition and the system can no longer maintain a spontaneous magnetization, although it still responds paramagnetically to an external field.

The clearance of the pathogens, either treatment-induced or spontaneous, it can be influenced by the genetic variants carried by the individual patients.

Emission can be spontaneous or stimulated.

Mutagenesis may occur endogenously, for example through spontaneous hydrolysis, or through normal cellular processes that can generate reactive oxygen species and DNA adducts, or through error in replication and repair.

These random sequences can be defined as sudden and spontaneous changes in the cell.

He derived the phrase spontaneous order from Gestalt psychology, and it was adopted by the classical liberal economist Frederick Hayek, although the concept can be traced back to at least Adam Smith.

" Similarly, all level II bubble universes with different physical constants can in effect be found as " worlds " created by " splits " at the moment of spontaneous symmetry breaking in a level III multiverse.

Free neutrons, in particular from spontaneous fissions, can cause the device to undergo a preliminary chain reaction that destroys the fissile material before it is ready to produce a large explosion, which is known as predetonation.

Orgasms can be multiple or spontaneous, and some non-sexual activity may result in a spontaneous orgasm.

Allegedly, humans can also ignite and burn without an obvious cause ; this phenomenon is known as spontaneous human combustion.

The rate of spontaneous emission ( i. e., the radiative rate ) can be described by Fermi's golden rule.

Actions of this kind can be ascribed to anger or envy, or to spontaneous, opportunistic behaviour – possibly for peer acceptance or bravado in gang cultures, or disgruntlement with the target ( victim ) person or society.

It is also essential that ontological causality does not suggest the temporal relation of before and after-between the cause and the effect ; that spontaneity ( in nature ) and chance ( in the sphere of moral actions ) are among the causes of effects belonging to the efficient causation, and that no incidental, spontaneous, or chance cause can be prior to a proper, real, or underlying cause per se.

Bangkok can be seen as an example of spontaneous order