NOTE: If two electrons are positioned in the same energy state then they should be positioned with opposite spines. Pauli’s exclusion principle: this principle states that no two electrons can have all the four quantum numbers mentioned above to be the same or similar.
At that point, the General Conference on Weights and Measures (CGPM), the SI’s governing body, decided to define h as its precisely measured numerical value, which then defines the kilogram 1 1. The new definition became possible when the best two measurements of h, the Kibble balance and the silicon spheres, reached an accuracy similar to the mass drift of the urkilogram over 130 years. (See the article by David Newell, Physics Today, July 2014, page 35.) The most profound change in units is the kilogram, which is no longer defined by the artifact in Paris but by the fixed value of Planck’s constant h = 6.626 070 15 × 10 −34 kg m 2/s. All prototype-based definitions have now been replaced with ones based on the cesium atom and fundamental constants.