Balkans vs chain of mountains

Balkans and chain of mountains both are nouns.

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

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