Hf vs hafnium

Hf and hafnium both are nouns.

Word	Noun	Adjective	Verb	Adverb
Hf	Yes	No	No	No
hafnium	Yes	No	No	No

As nouns, Hf and hafnium are synonyms defined as:

Hf and hafnium: a grey tetravalent metallic element that resembles zirconium chemically and is found in zirconium minerals; used in filaments for its ready emission of electrons

Other synonyms of Hf include atomic number 72.

Hf (noun)	hafnium (noun)
a grey tetravalent metallic element that resembles zirconium chemically and is found in zirconium minerals; used in filaments for its ready emission of electrons	a grey tetravalent metallic element that resembles zirconium chemically and is found in zirconium minerals; used in filaments for its ready emission of electrons