Young-Earth creationists -- that is, creationists who believe that Earth is no more than 10,000 years old -- are fond of attacking radiometric dating methods as being full of inaccuracies and riddled with sources of error.

Since all atoms of the same element have the same number of protons, different nuclides of an element differ in the number of neutrons they contain.

For example, hydrogen-1 and hydrogen-2 are both nuclides of the element hydrogen, but hydrogen-1's nucleus contains only a proton, while hydrogen-2's nucleus contains a proton and a neutron.

After emission, it quickly picks up two electrons to balance the two protons, and becomes an electrically neutral helium-4 (He4) atom. When an atom emits a beta particle, a neutron inside the nucleus is transformed to a proton.

The mass number doesn't change, but the atomic number goes up by 1.

Protons and neutrons together are called nucleons, meaning particles that can appear in the atomic nucleus.

A nuclide of an element, also called an isotope of an element, is an atom of that element that has a specific number of nucleons.

The decay rate and therefore the half-life are fixed characteristics of a nuclide. Thats the first axiom of radiometric dating techniques: the half-life of a given nuclide is a constant.

(Note that this doesnt mean the half-life of an element is a constant.

The mass number doesnt change, while the atomic number goes down by 1.