Physicists create world's smallest engine

Theoretical physicists at Trinity College Dublin are among an international collaboration that has built the world's smallest engine—which, as a single calcium ion, is approximately ten billion times smaller than a car ...

Shift to renewable electricity a win-win at statewide level

Amid rollbacks of the Clean Power Plan and other environmental regulations at the federal level, several U.S. states, cities, and towns have resolved to take matters into their own hands and implement policies to promote ...

Energy level

A quantum mechanical system or particle that is bound, confined spatially, can only take on certain discrete values of energy, as opposed to classical particles, which can have any energy. These values are called energy levels. The term is most commonly used for the energy levels of electrons in atoms or molecules, which are bound by the electric field of the nucleus. The energy spectrum of a system with energy levels is said to be quantized.

If the potential energy is set to zero at infinity, the usual convention, then bound electron states have negative potential energy.

Energy levels are said to be degenerate, if the same energy level is obtained by more than one quantum mechanical state. They are then called degenerate energy levels.

This text uses material from Wikipedia, licensed under CC BY-SA