IUPAC definition : a pure chemical substance composed of atoms with the same number of protons in the
atomic nucleus. sometimes this concept is called the elementary substance as distinct
from the chemical element as defined under 1, but mostly the term chemical element
is used for both concepts.; a species of atoms; all atoms with the same number of protons in the atomic nucleus.;
a pure chemical substance composed of atoms with the same number of protons in the
atomic nucleus. sometimes this concept is called the elementary substance as distinct
from the chemical element as defined under 1, but mostly the term chemical element
is used for both concepts. a species of atoms; all atoms with the same number of protons in the atomic nucleus.
Currated CISMeF NLP mapping