There are two main applications for radiometric dating.

The illustration below shows the three isotopes of carbon.

Some isotopes of certain elements are unstable; they can spontaneously change into another kind of atom in a process called “radioactive decay.” Since this process presently happens at a known measured rate, scientists attempt to use it like a “clock” to tell how long ago a rock or fossil formed.

The procedures used are not necessarily in question. The secular (evolutionary) worldview interprets the universe and world to be billions of years old. The use of carbon-14 dating is often misunderstood.

Carbon-14 is mostly used to date once-living things (organic material). Carbon-14 is constantly being added to the atmosphere.

Recall that atoms are the basic building blocks of matter.

Atoms are made up of much smaller particles called protons, neutrons, and electrons.

For example, all carbon atoms have 6 protons, all atoms of nitrogen have 7 protons, and all oxygen atoms have 8 protons.

The number of neutrons in the nucleus can vary in any given type of atom.

The atomic number corresponds to the number of protons in an atom.

Atomic mass is a combination of the number of protons and neutrons in the nucleus.

It cannot be used directly to date rocks; however, it can potentially be used to put time constraints on some inorganic material such as diamonds (diamonds could contain carbon-14). Cosmic rays from outer space, which contain high levels of energy, bombard the earth’s upper atmosphere.