Though every element has a specific number of protons and electrons, the number of neutrons varies within the same element. These variations are called isotopes (Learn on the isotopes definition). On the periodic table, the atomic mass of an element is closest to the element’s most common isotope. There are many applications for isotopes, many of them utilizing the unique properties radioactive elements.
One use of radioactive isotopes, or radioisotopes, is exploited in smoke detectors. Smoke detectors contain a small amount of americium-241, meaning the americium atoms have an atomic mass of 241. Smoke detectors use americium-241 to ionize, or electrically charge, particles in the air. The detector is then able run an electric current through the air using the power from the battery. When smoke enters this electrically charged air, the air becomes neutralized. The lack of an electric current causes the smoke detector to set off an alarm.
Another application of isotopes is carbon dating, which uses the isotope carbon-14. The process works like this. Every living organism has a specific concentration of carbon-12 and carbon-14 in its cells. When an organism dies, it has the most carbon-14 that it will ever have. As the dead organism decays, so does the amount of carbon-14 in its cells. Carbon-14 has a half-life of 5700 years, meaning after 5700 years, half of the amount of carbon will have decomposed to carbon-13 or carbon-12. Scientists can analyze the amount of carbon-14 in the cells of an organism to ascertain when an organism died.
A third employment of radioisotopes is used in food irradiation. This is the process of exposing food to gamma rays emitted by radioactive particles to kill bacteria. While the rays are strong enough to kill bacteria, they are not strong enough to alter the genetic material of the food or make it radioactive. A common isotope used in food irradiation is cobalt-60.
Another extremely important use of isotopes is bone imaging. For this process, doctors use technetium-99, which has a half-life of only six hours. They inject the isotopes into the patients body, and the energy given off by the isotopes is absorbed by the patient’s bones. This absorption of energy causes the bones to literally glow. A bone scanner then analyzes this glow and creates an image of the bones.
These are some of the main uses of isotopes, though there are many others. Isotopes allow us to obtain exactly what we want from an element because of the slight difference in chemical composition. Therefore, their uses in technology are limitless.
