9514 1404 393
Answer:
A) 448 mg
B) 3.5 mg
Step-by-step explanation:
24 days is 24/4 = 6 half-lives. That is, the mass of 7 mg is 2^-6 times the initial mass.
A) The initial mass is 2^6×(7 mg) = 448 mg
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B) 4 weeks is 28 days, or 7 half-lives. The remaining mass will be half the amount after 6 half-lives.
(7 mg)/2 = 3.5 mg . . . . remaining after 4 weeks
D) The original population of State A was one -fourth the times of the orignal population of State B
90%
convert the fraction know as a ratio to get 90%
6 minutes
1 minute times six
