ytterbium vs Yb

ytterbium and Yb both are nouns.

Word	Noun	Adjective	Verb	Adverb
ytterbium	Yes	No	No	No
Yb	Yes	No	No	No

As nouns, ytterbium and Yb are synonyms defined as:

ytterbium and Yb: a soft silvery metallic element; a rare earth of the lanthanide series; it occurs in gadolinite and monazite and xenotime

Other synonyms of ytterbium include atomic number 70.

ytterbium (noun)	Yb (noun)
a soft silvery metallic element; a rare earth of the lanthanide series; it occurs in gadolinite and monazite and xenotime	a unit of information equal to 1000 zettabits or 10^24 bits
	a soft silvery metallic element; a rare earth of the lanthanide series; it occurs in gadolinite and monazite and xenotime