expected value vs first moment

expected value and first moment both are nouns.

Word	Noun	Adjective	Verb	Adverb
expected value	Yes	No	No	No
first moment	Yes	No	No	No

As nouns, expected value and first moment are synonyms defined as:

expected value and first moment: the sum of the values of a random variable divided by the number of values

Other synonyms of expected value include arithmetic mean, expectation.

expected value (noun)	first moment (noun)
the sum of the values of a random variable divided by the number of values	the sum of the values of a random variable divided by the number of values