how are naturally occurring radioactive elements, such as Potassium-40, used to
date igneous rock? how
does this work when the rock solidifies, how the rock changes over time, and how a scientist can interpret these changes to date the rock. what is an example of a parent/daughter pair of elements, and why does the age of the rock start when the rock solidified and not when the atoms in the rock were formed inside a star in the distant past?