Here's why:
* Abstract nouns refer to concepts, ideas, qualities, or states of being. They cannot be touched or seen.
* "Nation" represents a group of people united by shared factors like language, culture, history, or territory. It's not a physical entity you can hold in your hand.
Examples:
* Concrete noun: "The flag of the nation is red, white, and blue." (Flag is a physical object)
* Abstract noun: "The nation is facing economic challenges." (Nation is a concept)