government activity vs federal

government activity is a noun but federal is not a noun.

Word	Noun	Adjective	Verb	Adverb
government activity	Yes	No	No	No
federal	No	Yes	No	No

government activity (noun)	federal (noun)
the act of governing; exercising authority

government activity (adjective)	federal (adjective)
	characterized by or constituting a form of government in which power is divided between one central and several regional authorities
	of or relating to the central government of a federation
	national; especially in reference to the government of the United States as distinct from that of its member units