There is yet another form of hydrogen called tritium, of which only very tiny amounts exist in air and water. Tritium is composed of one proton and two neutrons, but is still hydrogen because it only has a single proton. A small percentage of any carbon in anything living is of the isotope carbon-14. By measuring how much carbon-14 is in the object and comparing it to what we would find in a living object of the same type we can work out how old the object is. Lastly, we need a quick way to show which element and isotope we are talking about.
Many elements have their name reduced to the just the first letter, or first two letters.
We now need a way to show which isotope we are dealing with. An accepted way to do this is to show the number of protons at the bottom left of the element name and the total number of particles in the nucleus at the top left of the element name. Return to the Top of the Page. This form of radioactive decay is usually shown using the Greek letter for alpha. In doing so the parent atom decays into a lighter particle.