hydrargyrum vs atomic number 80

hydrargyrum and atomic number 80 both are nouns.

Word	Noun	Adjective	Verb	Adverb
hydrargyrum	Yes	No	No	No
atomic number 80	Yes	No	No	No

As nouns, hydrargyrum and atomic number 80 are synonyms defined as:

hydrargyrum and atomic number 80: a heavy silvery toxic univalent and bivalent metallic element; the only metal that is liquid at ordinary temperatures

Other synonyms of hydrargyrum include Hg, mercury, quicksilver.

hydrargyrum (noun)	atomic number 80 (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