A Rydberg atom is an atom with one or more electrons that have a high principal quantum number. Essentially, this means that the electrons occupy an electron shell further from the atom, and spend time further from the nucleus. These electrons have much higher energy and are less bound to their nucleus. Because of their behavior, they tend to stay in the classical planar orbits around the nucleus. This means that the Bohr model is still applicable today for describing the behavior of electrons in Rydberg atoms. Because the electrons are so far from the nucleus, typically the Rydberg atoms behave like their their normal counterparts in some aspects. Rydberg atoms react in an exaggerated manner when an electromagnetic field is applied. These atoms are able to form crystalline structures, typically hexagonal in shape. In Rydberg matter, as these planar structures are called, the electrons with a high principal quantum number become delocalized and form an electron medium, grey in the image above, around the core ions of the Rydberg atoms. Rydberg matter can last from a few seconds to the age of the universe. As the principal quantum number increases, the matter gets more stable. If the electrons that make up the medium have a principal quantum number of 12, meaning the electron is twelve electron shells out, the structure lasts for half a minute, but if the principal quantum number is …show more content…
A supercritical fluid is a substance whose temperature and pressure are above their critical points. The image on the left shows the relative location of the supercritical state for carbon dioxide. Supercritical fluids take on the of both gases and liquids. They effuse like gases, dissolve like liquids, and change density rapidly in response to temperature and pressure changes. They typically have a density, viscosity, and diffusivity (a substance’s ability to diffuse) that is in-between gases and liquids. Supercritical fluids have no surface tension, and are