Most of the elements in nature are stable and do not change.
However, some elements are not completely stable in their natural state.
It has become increasingly clear that these radiometric dating techniques agree with each other and as a whole, present a coherent picture in which the Earth was created a very long time ago.
Further evidence comes from the complete agreement between radiometric dates and other dating methods such as counting tree rings or glacier ice core layers.
Rocks are made up of many individual crystals, and each crystal is usually made up of at least several different chemical elements such as iron, magnesium, silicon, etc.When the glass is turned over, sand runs from the top to the bottom.Radioactive atoms are like individual grains of sand--radioactive decays are like the falling of grains from the top to the bottom of the glass.Radiometric dating techniques indicate that the Earth is thousands of times older than that--approximately four and a half billion years old.Many Christians accept this and interpret the Genesis account in less scientifically literal ways.