ionisation vs ionise

ionisation is a noun but ionise is not a noun.

Word	Noun	Adjective	Verb	Adverb
ionisation	Yes	No	No	No
ionise	No	No	Yes	No

ionisation (noun)	ionise (noun)
the process of ionizing; the formation of ions by separating atoms or molecules or radicals or by adding or subtracting electrons from atoms by strong electric fields in a gas
the condition of being dissociated into ions (as by heat or radiation or chemical reaction or electrical discharge)

ionisation (verb)	ionise (verb)
	convert into ions
	become converted into ions