Chest radiograph. A chest radiograph, colloquially called a chest X-ray (CXR), or chest film, is a projection radiograph of the chest used to diagnose conditions affecting the chest, its contents, and nearby structures. Chest radiographs are the most common film taken in medicine.
Helium is a chemical element with symbol He and atomic number 2. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas that heads the noble gas group in the periodic table. Its boiling and melting points are the lowest among all the elements.he nucleus of the helium-4 atom is identical with an alpha particle. High-energy electron-scattering experiments show its charge to decrease exponentially from a maximum at a central point, exactly as does the charge density of helium's own electron cloud.
How would we proceed in building the nucleus of higher elements, such as helium, lithium, etc., and various isotopes? Notice the deuteron has a down-quark protruding at either end. A logical step would be to attach a proton to one of these. This would give the following: What we now have is a Helium-3 nucleus, consisting of two protons and a neutron. Helium-3 is known to be a stable isotope of Helium, and from a visual perspective at least, it does appear stable. Just as with deuterium, this Helium-3 structure will need to rotate in order to hold the up-quarks at an altitude.