chunk vs group

chunk and group both are nouns.

Word	Noun	Adjective	Verb	Adverb
chunk	Yes	No	Yes	No
group	Yes	No	Yes	No

As verbs, group is a hypernym of chunk; that is, group is a word with a broader meaning than chunk:

chunk (noun)	group (noun)
a compact mass	any number of entities (members) considered as a unit
a substantial amount	a set that is closed, associative, has an identity element and every element has an inverse
	(chemistry) two or more atoms bound together as a single unit and forming part of a molecule

chunk (verb)	group (verb)
group or chunk together in a certain order or place side by side	arrange into a group or groups
put together indiscriminately	form a group or group together