The answer is letter A definitively .
Answer: 20 mg Te-99 remains after 12 hours.
Explanation: N(t) = N(0)*(1/2)^(t/t1/2)
N(t) = (80 mg)*(0.5)^(12/6)
N(t) = 20 mg remains after 12 hours
Answer:
7. .........................
Answer:
a b
Explanation:
I think so take it with a grain of salt
