Answer:
0.78125g
Step-by-step explanation:
Since there are 35 days in 5 weeks, 7 half-lives of Bismuth-210 will take place. To solve for that, you can divide 100g by 2, 7 times or simply: [tex]\frac{100}{2^{7}}[/tex]
[tex]\frac{100}{2} =50\\\frac{50}{2} =25\\\frac{25}{2} =12.5\\\frac{12.5}{2} =6.25\\\frac{6.25}{2} =3.125\\\frac{3.125}{2} =1.5625\\\frac{1.5625}{2} =0.78125[/tex]