The corresponding half lives for each plotted point are marked on the line and identified.It can be readily seen from the plots that when this procedure is followed with different amounts of Rb87 in different minerals, if the plotted half life points are connected, a straight line going through the origin is produced. The steeper the slope of the isochron, the more half lives it represents.

radioactive isotope used for age dating-88

(Note that this does not mean that the ratios are the same everywhere on earth.

It merely means that the ratios are the same in the particular magma from which the test sample was later taken.) As strontium-87 forms, its ratio to strontium-86 will increase.

Strontium-86 is a stable element that does not undergo radioactive change.

In addition, it is not formed as the result of a radioactive decay process.

An atom with the same number of protons in the nucleus but a different number of neutrons is called an isotope.

For example, uranium-238 is an isotope of uranium-235, because it has 3 more neutrons in the nucleus.

The creationist "argon escape" theory does not support their young earth model.) The argon age determination of the mineral can be confirmed by measuring the loss of potassium.

In old rocks, there will be less potassium present than was required to form the mineral, because some of it has been transmuted to argon.

The amount of strontium-86 in a given mineral sample will not change.