No, normally it occurs at temperatures of millions of degrees. It does occur at room temperature, but not in significant amount; any possible practical use of "cold fusion" is, so far, speculation.
No, while it is hot enough the pressure is too low.
It stops at about 0.12 seconds.
The onset of fusion reactions inside stars requires high density and high temperature. The high density is needed to bring atomic nuclei close enough together for the strong nuclear force to overcome electrostatic repulsion, allowing the nuclei to fuse. The high temperature is required to provide the particles with enough kinetic energy to overcome the electrical repulsion and fuse.
Stars are powered by nucliar fussion. There is minimum pressure and temperature requirement in order to start the process. So to became Star the object has to have enought mass to increase its internal temperature and pressure.
The proton-proton chain requires high temperatures, typically around 15 million Kelvin, to overcome the electrostatic repulsion between positively charged protons. At these elevated temperatures, protons have enough kinetic energy to collide with sufficient force to allow the strong nuclear force to take over, enabling fusion to occur. This process is essential for stars like the Sun, where the energy produced through fusion is what powers them. Without such high temperatures, the likelihood of fusion events occurring would be extremely low.
No, while it is hot enough the pressure is too low.
The rest of the sun is too cold and too low pressure.
Low mass stars are created in the same way as all other stars, with one exception. They do not accumulate enough mass to create enough pressure in the core for nuclear fusion to occur. They "glow" because of the external pressure on the core but this is not enough to initiate nuclear fusion.
This process would occur during a nuclear fusion reaction. In nuclear fusion, lighter atomic nuclei combine to form a heavier nucleus, releasing a large amount of energy in the process. Fusion reactions are responsible for powering the sun and other stars.
Nuclear fusion produces very little waste compared to nuclear fission. The waste produced by nuclear fusion is mainly low-level radioactive material, which is easier to manage and has a shorter lifespan.
Nuclear fusion of light elements is the process operating in the stars to produce energy, and needs very high temperature to occur. Experiments on earth to aim at producing useful power from fusion have been progressing for many years. The reactants most likely to be used are isotopes of hydrogen, deuterium and tritium. These need to be heated to some hundreds of millions of degrees kelvin before reaction starts. Fusion reactions have been seen, but only for less than 1 second so far. Fusion is not a chemical reaction, it is a nuclear process.
It stops at about 0.12 seconds.
The onset of fusion reactions inside stars requires high density and high temperature. The high density is needed to bring atomic nuclei close enough together for the strong nuclear force to overcome electrostatic repulsion, allowing the nuclei to fuse. The high temperature is required to provide the particles with enough kinetic energy to overcome the electrical repulsion and fuse.
Contraction occur at low temperature.
Under the worst possible conditions, a meltdown can occur in a nuclear submarine. It is an event of low probability, however.
No, two nuclei do not combine to form one nucleus in nuclear fission. It is the process of nuclear fusion that speaks to the combination of two nuclei to form one nucleus. The two nuclei are fused to form a new nucleus. Nuclear fission is the "breaking" or "splitting" of an atomic nucleus into two (or possibly more) smaller fragments.
I do not understand what you are asking because of a definition problem. A nuclear bomb can be either a fission or fusion bomb. Also a physical crash of nuclear devices is most likely to simply detonate their conventional explosives regardless of whether they are fission or fusion (although modern low shock sensitivity explosives make this less likely than it was).