methylene vs methylene group

methylene and methylene group both are nouns.

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

As nouns, methylene and methylene group are synonyms defined as:

methylene and methylene group: the bivalent radical CH2 derived from methane

Other synonyms of methylene include methylene radical.

methylene (noun)	methylene group (noun)
the bivalent radical CH2 derived from methane	the bivalent radical CH2 derived from methane