chain of mountains vs Balkans

chain of mountains and Balkans both are nouns.

Word	Noun	Adjective	Verb	Adverb
chain of mountains	Yes	No	No	No
Balkans	Yes	No	No	No

chain of mountains (noun)	Balkans (noun)
a series of hills or mountains	the Balkan countries collectively
	a large peninsula in southeastern Europe containing the Balkan Mountain Range
	the major mountain range of Bulgaria and the Balkan Peninsula