arsenic vs arsenical

arsenic and arsenical both are nouns.

Word	Noun	Adjective	Verb	Adverb
arsenic	Yes	No	No	No
arsenical	Yes	Yes	No	No

arsenic (noun)	arsenical (noun)
a very poisonous metallic element that has three allotropic forms; arsenic and arsenic compounds are used as herbicides and insecticides and in various alloys; found in arsenopyrite and orpiment and realgar	a pesticide or drug containing arsenic
a white powdered poisonous trioxide of arsenic; used in manufacturing glass and as a pesticide (rat poison) and weed killer

arsenic (adjective)	arsenical (adjective)
	relating to or containing arsenic