In many cases, the daughter nuclide itself is radioactive, resulting in a decay chain, eventually ending with the formation of a stable (nonradioactive) daughter nuclide; each step in such a chain is characterized by a distinct half-life.
It is therefore essential to have as much information as possible about the material being dated and to check for possible signs of alteration.
Precision is enhanced if measurements are taken on multiple samples from different locations of the rock body.
A fourth form, buckminsterfullerene, formula C, whose framework is reminiscent of the seams in an Association Football ("soccer") ball, is the subject of considerable interest at present and was only discovered a few years ago in work involving Harry Kroto, a Sheffield graduate.
Sometime prior to the autumn of 1803, the Englishman John Dalton was able to explain the results of some of his studies by assuming that matter is composed of atoms and that all samples of any given compound consist of the same combination of these atoms.
It is not affected by external factors such as temperature, pressure, chemical environment, or presence of a magnetic or electric field.
The only exceptions are nuclides that decay by the process of electron capture, such as beryllium-7, strontium-85, and zirconium-89, whose decay rate may be affected by local electron density.
Carbon as diamond has also been known since very ancient times.
The recognition that soot (amorphous carbon), graphite (another form of carbon) and diamond are all forms of carbon.
Different methods of radiometric dating vary in the timescale over which they are accurate and the materials to which they can be applied.
All ordinary matter is made up of combinations of chemical elements, each with its own atomic number, indicating the number of protons in the atomic nucleus.
This transformation may be accomplished in a number of different ways, including alpha decay (emission of alpha particles) and beta decay (electron emission, positron emission, or electron capture).