Why is u 238 used for dating rocks
Droughts and other variations in the climate make the tree grow slower or faster than normal, which shows up in the widths of the tree rings.
These tree ring variations will appear in all trees growing in a certain region, so scientists can match up the growth rings of living and dead trees.
Both are unstable and radioactive, shedding nuclear particles in a cascade that doesn't stop until they become lead (Pb).
In regions outside the tropics, trees grow more quickly during the warm summer months than during the cooler winter.
This pattern of growth results in alternating bands of light-colored, low density "early wood" and dark, high density "late wood".
Radioisotope dating (also referred to as radiometric dating) is the process of estimating the age of rocks from the decay of their radioactive elements.
There are certain kinds of atoms in nature that are unstable and spontaneously change (decay) into other kinds of atoms.