closed shell

noun

, Physics.

1. (in atomic structure) a shell that contains the maximum number of electrons permitted by the exclusion principle.
2. (in nuclear structure) a shell that contains the maximum number of nucleons permitted by the exclusion principle.

Example Sentences

Most of them will have tightly closed shells, but some may be “gaping,” meaning they are reacting to their environment or have died.

From Washington Post

A tightly closed shell indicates that they are alive, whereas a slightly open shell proves that they are dead.

From Project Gutenberg