This could have many names such as 'decay', 'radioactive decay', or 'radiation.
The laser causes the stimulated emission of radiation. The light emitted is monochromatic and coherent,that is plane polarised. I imagine that spontaneous emission occurs in a Light emitting diode ,monochromatic but not polarised. Hope this is of help
This physical phenomenon is called radioactivity.
Spontaneous radiation is incoherent because it occurs randomly with no fixed phase relationship between emitted photons. This randomness results in a broad range of frequencies and directions for the emitted radiation, making it incoherent.
Spontaneous emission occurs randomly and naturally when an excited atom transitions to a lower energy state, releasing a photon in the process. Stimulated emission, on the other hand, is induced by the presence of external photons that cause an already excited atom to release a second identical photon. In spontaneous emission, the emitted photon may have any frequency within the spectral line width of the transition. In stimulated emission, the emitted photon has the same frequency, phase, direction, and polarization as the stimulating photon. Spontaneous emission is non-coherent and occurs independently of external radiation. In contrast, stimulated emission is a coherent process that contributes to the amplification of light in lasers. The rate of spontaneous emission is independent of the intensity of external radiation, while the rate of stimulated emission is directly proportional to the intensity of the stimulating radiation. Spontaneous emission plays a role in processes like fluorescence and phosphorescence, whereas stimulated emission is the principle behind the operation of lasers.
It's a semantic thing - by definition, if something gives out radiation, then it is radioactive. If an element gives off radiation, then it is a 'radioactive' element. If it does not give out radiation, then it is not 'radioactive'.
That's why it's called spontaneous emission you cannot control it. But there is a kind of emission which is called stimulated emission emission. People use stimulated emission in lasers and it can be controlled.
stimulated emission causes due to the energy difference between the higher and lower energy level state, but it doesn't depends in the case of spontaneous emission . spontaneous emission causes without any stimulation .In stimulated emission energy transfer is twice the energy transfer of spontaneous emission.
an element subject to spontaneous degeneration of its nucleus accompanied by the emission of alpha particles, beta particles, or gamma rays.
Spontaneous emission of ionizing radiation as a consequence of a nuclear reaction, or directly from the breakdown of an unstable nucleus; The radiation so emitted; including gamma rays, alpha particles, neutrons, electrons, positrons, etc
No, radioactivity is not considered a chemical property. It is a physical property related to the spontaneous emission of radiation from an unstable atomic nucleus.
stimulated emission causes due to the energy difference between the higher and lower energy level state, but it doesn't depends in the case of spontaneous emission . spontaneous emission causes without any stimulation .In stimulated emission energy transfer is twice the energy transfer of spontaneous emission.
The isotope thorium-232 is an alpha emitter; extremely rare are decays by spontaneous fission or double beta emission.