Answer:
[tex]Age=1040.55 million\ years[/tex]
Explanation:
From the question we are told that:
Initial Rock atoms [tex]a_1=2200atoms of 235^U[/tex]
Final Rock atom [tex]a_2=800 of 235^U[/tex]
Age of half life 713 million years
Generally the equation for Age is mathematically given by
[tex]\frac{1}{2^n}=\frac{800}{2200}[/tex]
[tex]\frac{1}{2^n}=\frac{1}{2.750}[/tex]
[tex]n=1.46[/tex]
Therefore
[tex]Age=713*1.46[/tex]
[tex]Age=1040.55 million\ years[/tex]