Problems with radiometric dating of rocks

The meaning of this equation is that the rate of change of the number of nuclei over time is proportional only to the number of nuclei.

This is consistent with the assumption that each decay event is independent and its chance does not vary over time.

This method for rock dating is based on the decay of potassium-40 into argon: until the rock solidifies, argon can escape, so it can in theory date the formation of rock.One problem is that potassium is also highly mobile and may move into older rocks.The half-life of carbon-14 is approximately 5,730 years. Since the quantity represents 13% (or 13/100ths) of , it follows that This is based on the decay of rubidium isotopes to strontium isotopes, and can be used to date rocks or to relate organisms to the rocks on which they formed.It suffers from the problem that rubidium and strontium are very mobile and may easily enter rocks at a much later date to that of formation.radiometric ages that appear older than they should are explained by saying the clock was not reset.

contradicted by evidence that suggests the ratio of parent and daughter material in volcanic rock varies and is unpredictable...(Closed System) suggests that the material being tested has not gained or lost parent or daughter material since it formed.

The half-life , specific to each nuclide, can be accurately measured on a pure sample, and is known to be independent of the chemical composition of the sample, temperature and pressure.

Through analysis, a bone fragment is determined to contain 13% of its original carbon-14.

Radiometric dating has been used to determine the ages of the Earth, Moon, meteorites, ages of fossils, including early man, timing of glaciations, ages of mineral deposits, recurrence rates of earthquakes and volcanic eruptions, the history of reversals of Earth's magnetic field, and many of other geological events and processes.

Although the time at which any individual atom will decay cannot be forecast, the time in which any given percentage of a sample will decay can be calculated to varying degrees of accuracy.

Radioactive elements are unstable; they breakdown spontaneously into more stable atoms over time, a process known as radioactive decay.