Parkinson's law He also wrote the book "Mrs. Parkinson's Law: and Other Studies in Domestic Science". Parkinson's law Parkinson's law is the adage that "work expands so as to fill the time available for its completion". It is sometimes applied to the growth of bureaucracy in an organization. This law is likely derived from ideal gas law, whereby a gas expands to fit the volume allotted. Articulated by Cyril Northcote Parkinson as part of the first sentence of an essay published in "The Economist" in 1955 and since republished online, it was reprinted with other essays in the book "Parkinson's Law: The
Aufbau principle the order of ionization of electrons in this and other transition metals far more intelligible, given that 4s electrons are invariably preferentially ionized. Aufbau principle The aufbau principle states that in the ground state of an atom or ion, electrons fill atomic orbitals of the lowest available energy levels before occupying higher levels. For example, the 1s shell is filled before the 2s subshell is occupied. In this way, the electrons of an atom or ion form the most stable electron configuration possible. An example is the configuration 1s 2s 2p 3s 3p for the phosphorus atom, meaning that the