How is half-life related to the decay constant?


Here, the decay constant is tex2html_wrap_inline47, the half-life is T, tex2html_wrap_inline51 is the starting number of parent atoms, and ``ln'' means natural logarithm (as opposed to the logarithm in base 10).

Dating Rocks

How can we date rocks, if we know the number of parent and daughter atoms and the decay constant?


Here, tex2html_wrap_inline47 is the decay constant, P(t) is the number of ``parent'' atoms at time t, D(t) is the number of ``daughter'' (why not son?) atoms at time t, ``ln'' again means natural logarithm, and t is the age of the rock.