Radiometric dating of sediments
In alpha decay, the radioactive atom emits an alpha particle.An alpha particle contains two protons and two neutrons.Thats the essence of radiometric dating: measure the amount thats present, calculate how much is missing, and Obviously, the major question here is "how much of the nuclide was originally present in our sample? If an element has more than one nuclide present, and a mineral forms in a magma melt that includes that element, the elements different nuclides will appear in the mineral in precisely the same ratio that they occurred in the environment where and when the mineral was formed. The third and final axiom is that when an atom undergoes radioactive decay, its internal structure and also its chemical behavior change.Losing or gaining atomic number puts the atom in a different row of the periodic table, and elements in different rows behave in different ways. C14 is radioactive, with a half-life of 5730 years.
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.
Radiometric dating methods are the strongest direct evidence that geologists have for the age of the Earth.
All these methods point to Earth being very, very old -- several billions of years old.
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.