quicksilver vs Hg

quicksilver and Hg both are nouns.

Word	Noun	Adjective	Verb	Adverb
quicksilver	Yes	Yes	No	No
Hg	Yes	No	No	No

As nouns, quicksilver and Hg are synonyms defined as:

quicksilver and Hg: a heavy silvery toxic univalent and bivalent metallic element; the only metal that is liquid at ordinary temperatures

Other synonyms of quicksilver include atomic number 80, hydrargyrum, mercury.

quicksilver (noun)	Hg (noun)
a heavy silvery toxic univalent and bivalent metallic element; the only metal that is liquid at ordinary temperatures	a heavy silvery toxic univalent and bivalent metallic element; the only metal that is liquid at ordinary temperatures

quicksilver (adjective)	Hg (adjective)
liable to sudden unpredictable change