It would be the x-chromosome only, I believe.
Carbon-12 has 6 neutrons and 6 protons, making it 12.
Carbon-14 has 8 neutrons and 6 protons, making it 14.
It is used to date the age of things that are very old using radioactive isotopes.
It is known as Arthrodesis. It is the manufactured enlistment of joint hardening between two bones by surgery. This is done to ease recalcitrant agony in a joint which can't be overseen by torment medicine, braces, or other regularly showed medications. The average reasons for such agony are breaks which upset the joint, extreme sprains, and joint pain.
