Answer:
[tex]A=275.1g[/tex]
Explanation:
Hello.
In this case, since the radioactive decay is computed via:
[tex]A=A_0*2^{-\frac{t}{t_{1/2}}[/tex]
For the initial amount of Ra-226 (300 g), once 200 years have passed, the remaining mass is:
[tex]A=300g*2^{-\frac{200years}{1600years}}\\\\A=275.1g[/tex]
This is, considering that the half-life is 1600 years, it means that the mass of Ra-226 is decreased.
Best regards.
