attention vs alertness

attention and alertness both are nouns.

Word	Noun	Adjective	Verb	Adverb
attention	Yes	No	No	No
alertness	Yes	No	No	No

As nouns, alertness is a hyponym of attention; that is, alertness is a word with a more specific, narrower meaning than attention:

attention (noun)	alertness (noun)
the work of providing treatment for or attending to someone or something	lively attentiveness
a courteous act indicating affection	the process of paying close and continuous attention
a motionless erect stance with arms at the sides and feet together; assumed by military personnel during drill or review	a state of readiness to respond
the process whereby a person concentrates on some features of the environment to the (relative) exclusion of others
the faculty or power of mental concentration
a general interest that leads people to want to know more