Question

To determine the age of fairly recent fossils and organic artifacts, it is possible to analyze the amounts of the isotopes 14C and 14N, because over time the 14C—which originated in the atmosphere—breaks down into 14N. What net change occurred for this to happen?

Answer 1

Answer: The net change in the atoms is the conversion of a neutron to a proton, turning Carbon (6 protons) into Nitrogen (7 protons).

Explanation:

Carbon-14, generated from the atmosphere, has 6 protons and 8 neutrons. That's where the 14 comes from, called the mass number, is the sum of protons and neutrons (6+8=14).

Carbon-14 is radioactive and decays by beta decay. That means one of its neutrons spontaneously turns into a proton, an electron, and a neutrino, according to:

$^{14} C \rightarrow\ ^{14} N\ +\ e^- +\ neutrino$

After that, the atom has 7 protons and 7 neutrons, maintaining its mass number but changing its atomic number from 6 to 7, turning into Nitrogen.