High Quality Content by WIKIPEDIA articles! Sodium-24 (24Na) is one of the more important isotopes of sodium. It is radioactive and created from common sodium-23 by neutron bombardment. With a 15-hour half-life, 24Na decays to 24Mg by emission of an electron and two gamma rays. Exposure of the human body to intense neutron flux creates 24Na in blood plasma. Measurements of its quantity are used to determine the absorbed radiation dose of the patient. This is used to determine the level of medical treatment required.