Function: noun
Date: 1946
: an isotope of carbon of mass number 12 that is the most abundant carbon isotope and is used as a standard for measurements of atomic weight
Function: noun
Date: 1946
: an isotope of carbon of mass number 12 that is the most abundant carbon isotope and is used as a standard for measurements of atomic weight
Merriam Webster Collegiate English Dictionary. Merriam Webster - Энциклопедический словарь английского языка. 2012