With every electron stationed in its own orbital or paired off with each other in the higher energy level, the energy level is balanced and stable. The atoms that utilize this exception are Molybdenum, Chromium, Gold, Silver, and Copper.
This principles determines the manner in which atomic orbitals of an element filled with electrons. According to the principle, orbitals are filled by electrons on the basis of increasing order of orbital energy level. It can be used to determine the location of electrons in an atom.
However, chromium, silver, etc. are the exception because of the increased stability provided by the half-filled or filled sub-shells and also due to the presence of energy gap between the sub-shells.
Fission. When a large fissile atomic nucleus such as uranium-235 or plutonium-239 absorbs a neutron, it may undergo nuclear fission. The heavy nucleus splits into two or more lighter nuclei, (the fission products), releasing kinetic energy, gamma radiation, and free neutrons.
The word radon is derived from radium, of which radon is gas. Early in its discovery it was also called radium emanation and niton, which comes from the Latin nitens, Since 1923, however, it has been called radon.
