platinum vs Pt

platinum and Pt both are nouns.

Word	Noun	Adjective	Verb	Adverb
platinum	Yes	No	No	No
Pt	Yes	No	No	No

As nouns, platinum and Pt are synonyms defined as:

platinum and Pt: a heavy precious metallic element; grey-white and resistant to corroding; occurs in some nickel and copper ores and is also found native in some deposits

Other synonyms of platinum include atomic number 78.

platinum (noun)	Pt (noun)
a heavy precious metallic element; grey-white and resistant to corroding; occurs in some nickel and copper ores and is also found native in some deposits	a heavy precious metallic element; grey-white and resistant to corroding; occurs in some nickel and copper ores and is also found native in some deposits