Answer:
[tex]a_{n}[/tex]=209.09 mg
Step-by-step explanation:
given: material= radium
half life= 1590 years
initial mass [tex]a_{0}[/tex] =500mg
we know that to calculate the amount left we use
[tex]a_{n}[/tex] = [tex]a_{0}[/tex][tex]\left ( 0.5\right )^{n}[/tex]
[tex]n=\frac{2000}{1590} = 1.2578[/tex]
therefore
[tex]a_{n}[/tex] = [tex]500\times0.5^{1.2578}[/tex]
[tex]a_{n}[/tex]=209.09058407921 mg
[tex]a_{n}[/tex]=209.09 mg amount left after 2000 years