What isotopes of elements are used for radioactive dating
It is assumed that level of carbon-14 in the atmosphere is constant.
These are the surfaces that we can get absolute ages for.
This is called Therefore the characteristic property of the radioisotope, namely its radioactivity can act as a tag or label, which permits the fate of the element or its compound containing this element to be traced through a series of chemical or physical changes.
Some of the application of tracer techniques are discussed below.
When we age date a planet, we are actually just dating the age of the surface, not the whole planet.
We can get absolute ages only if we have rocks from that surface.