The half-life of Sodium-24 is 15 hours, and the half-life of Francium-223 is 22 minutes. How long will it take for a 200 g sample of Sodium-24 to decay to 25 g? please solve!! thank uuu

9514 1404 393

  45 hours

Step-by-step explanation:

The fraction remaining is ...

  (25 g)/(200 g) = 1/8

We recognize this value as (1/2)^3, meaning that 3 half-lives will have passed when that amount remains. (The amount remaining is multiplied by 1/2 each time a half-life passes.)

  3 half-lives is 3 × 15 hours = 45 hours

It will take 45 hours for 200 g of Sodium-24 to decay to 25 g.

correct

step-by-step explanation: