Direct radiometric dating volcanic rocks

is converted into another specific atom or isotope at a constant and known rate.Most elements exist in different atomic forms that are identical in their chemical properties but differ in the number of neutral particles— neutrons—in the nucleus.By way of explanation it can be noted that since the cause of the process lies deep within the atomic nucleus, external forces such as extreme heat and pressure have no effect.The same is true regarding gravitational, magnetic, and electric fields, as well as the chemical state in which the atom resides.

Likewise, the conditions that must be met to make the calculated age precise and meaningful are in themselves simple:1.

The half-life and the decay constant are inversely proportional because rapidly decaying radioisotopes have a high decay constant but a short half-life.

With to designate the parent atom, the expression assumes its familiar form:and This pair of equations states rigorously what might be assumed from intuition, that minerals formed at successively longer times in the past would have progressively higher daughter-to-parent ratios.

In short, the process of radioactive decay is immutable under all known conditions.

Although it is impossible to predict when a particular atom will change, given a sufficient number of atoms, the rate of their decay is found to be constant.