Question

The half-life of Palladium-100 is 4 days. After 12 days a sample of Palladium-100 has been reduced to a mass of 7 mg.

Answer 1

I think this is correct but im not sure..

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 = ?

Answer 2

• 56 mg

Explanation:

• Let the initial mass of sample is x mg

We have the following equation:

• x*
  `((1)/(2)) ^(12/4)`= 7
• x*
  `((1)/(2)) ^(3)` = 7
• x*
  `((1)/(8) )` = 7
• x = 7*8
• x = 56 mg