electron shell vs grouping

electron shell and grouping both are nouns.

Word	Noun	Adjective	Verb	Adverb
electron shell	Yes	No	No	No
grouping	Yes	No	No	No

As nouns, grouping is a hypernym of electron shell; that is, grouping is a word with a broader meaning than electron shell:

Other hypernyms of electron shell include group.

electron shell (noun)	grouping (noun)
a grouping of electrons surrounding the nucleus of an atom	any number of entities (members) considered as a unit
	the activity of putting things together in groups
	a system for classifying things into groups