Respuesta :

Answer:

I think this is correct but im not sure..

Step-by-step explanation:

12 days is 3 half-lives ... so, 1/8 initial ... (1/2)^3 = 1/8

... initial is 8 mg

4 weeks is 7 half-lives ... 8 mg * (1/2)^7 = ?

mhanifa

Answer:

  • 56 mg

Step-by-step explanation:

  • Let the initial mass of sample is x mg

We have the following equation:

  • x* [tex](\frac{1}{2}) ^{12/4}[/tex]= 7
  • x*[tex](\frac{1}{2}) ^{3}[/tex] = 7
  • x*[tex](\frac{1}{8} )[/tex] = 7
  • x = 7*8
  • x = 56 mg