Nuclear Physics

A chain reaction is more likely to occur in two pieces of uranium stuck together, as the increased proximity of the uranium atoms enhances the likelihood of neutron interactions and subsequent fission events. In contrast, when uranium is in two separate pieces, the distance between the atoms reduces the probability of neutron encounters, making a sustained chain reaction less probable.

The positive charges of hydrogen nuclei cause repulsion, it is very difficult to bring two hydrogen nuclei close enough for them to fuse into helium. However, if they can be forced to fuse, a huge amount of energy is released.

No, the si units for length are in meters.

Becquerel in 1896 discovered that uranium emit radiations.

The positron released from an atomic nucleus in positron emission (or beta plus decay) appears with high kinetic energy. It's moving very quickly, and because it is, it has an extremely low probability of actually interacting with that atom's electrons in mutual annihilation. That positron will undergo some scattering events to dump energy, and only then will the probability of it being able to actually "combine" with an electron increase to the point where it will actually do so.

They're two ways of expressing the same idea. A "color singlet" meson is a meson consisting of a red-antired, green-antigreen, or blue-antiblue quark-antiquark pair. Since X-antiX cancels out, this is essentially the same thing as saying that the meson has no net overall color charge ... that is, it's colorless.

It might be because of dust in the atmosphere elevated by the explosion. Particles of dust absorb and scatter visible light very well. And the sky turn to black because there is on light coming through dust clouds.

Gamma Radiation can be used in several ways in the medical industry and there have been many significant advances in this area. They can be used for curing cancers and other illnesses. They are used in a beam and aimed at the cancerous cells in the body. They kill the cells, but often, the gamma radiation will kill living cells, leading to permanent damage and could even prove fatal.

Tiny beta capsules can be used to treat cancer.

The capsules are injected around the cancer and the beta radiation kills the cancer cells. Radiation is particularly damaging to cells that are in the process of dividing. Cancer cells divide much more often than healthy cells. This means cancer cells tend to be killed while most of the healthy cells are unharmed.

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Changes in nuclear mass can happen when, say, radioactive decay occurs and a nucleus loses mass. When an unstable atomic nucleus "adjusts" to a new state, it dumps a particle or particles, and energy, and its mass decreases. Certainly nuclear fission will cause a dramatic reduction in nuclear mass, but this is the actual "breaking up" of a nucleus into smaller nuclei called fission fragments. Perhaps an example will help. The element radon is an inert gas, but it has no stable isotopes. It's most stable isotope, 222Rn, appears as a decay product of radium; it's a radioactive daughter. It turns out that 222Rn decays by alpha emission, and that means that two neutrons and two protons are kicked out of the nucleus. This will produce the radioactive daughter product polonium-218. It is possible for a nucleus to absorb a particle and gain mass. Frequently this will cause nuclear instability (if it doesn't actually initiate fission) and create a radionuclide, which is unstable and will eventually decay. But something like, say, neutron absorption (neutron capture) will result in an atomic nuclei with a greater mass than the original atomic nucleus that absorbed that neutron. It is of note that fusion knits smaller nuclei or particles together to create a larger nucleus, but this may not necessarily be considered a "simple increase" of mass in a nucleus, though the resultant nucleus will be heavier than any constituent nucuei or particles. You may want an example. If we stick some uranium-238 into an operating nuclear reactor, the 238U will absorb a neutron to become 239U, which is heavier by one neutron that the atomic nucleus that absorbed that neutron. (The 239U is unstable and decays in a couple of steps to make 239Pu, which is used as the fissile material in most nuclear bombs and as a fuel in some nuclear reactors.) Use the links below to related articles posted by our friends at Wikipedia, where knowledge is free.

A transglottic mass refers to a growth or lesion that extends through the vocal cords or glottis. This can cause hoarseness, voice changes, or breathing difficulties. Treatment options depend on the underlying cause of the mass.

The nucleus of a carbon atom is much smaller than the entire carbon atom itself. The nucleus contains protons and neutrons that account for the majority of the atom's mass, while electrons orbit around the nucleus in a relatively large atomic cloud.

No, X-rays do not all have the same energy. These powerful forms of electromagnetic energy have wavelengths of between 10 down to 0.01 nanometers, which is 3 x 1016 Hertz to 3 x 1019 Hertz (with corresponding energies from 120 eV to 120 keV).

In addition to a spectrum of wavelengths, frequencies and energies, we sometimes talk about "hard" and "soft" X-rays. The hard X-rays, so-called because they have greater penetrating power, have energies from about 12 to 120 keV (or have wavelengths of between 0.10 and 0.01 nanometers). The soft X-rays have energies from 0.12 keV to 12 keV (or have wavelengths from 10 to 0.10 nanometers).

For the investigator who wishes to know more about X-rays, a link is provided below to assist in getting up to speed on this form or electromagnetic energy.

You should never starve yourself; starvation diets will always fail and you will inevitably regain any weight lost. The only way to lose weight an keep it off is to eat healthy and get regular exercise.