Carbon 14 dating rocks
They have masses of 13 and 14 respectively and are referred to as "carbon-13" and "carbon-14." If two atoms have equal numbers of protons but differing numbers of neutrons, one is said to be an "isotope" of the other.Carbon-13 and carbon-14 are thus isotopes of carbon-12.This element is locked in tiny zircons within the granite. While it stays within the zircon for a period of time, being a very small atom, helium escapes the zircon within a few thousand years.When creation scientists studied granite samples, they made interesting discoveries.
Each helium nucleus has two protons and two neutrons.
The article is in straightforward language and the non-technical reader could profitably work through it.