K-shell

[ key-shel ]

noun

, Physics.

1. the first shell of electrons surrounding the nucleus of an atom and containing, when filled, two electrons having principal quantum number 1.

Word History and Origins

Origin of K-shell¹

First recorded in 1965–70

Example Sentences

However, because the K-shell transition lines of chromium and manganese are weak and those of iron and nickel are very close in photon energy, high-resolution spectroscopy is required for an accurate determination of the abundances of these elements.

From Nature