B is the answer to your question
Answer: 30g
Step-by-step explanation:
In this question (t½) of isotope is 40 days, which means that after 40 days half of the sample would have decayed and half would be left as it is.
After 40 days ( first half life) 240 /2 = 120 g decays and 120 g remains left.
After another 40 days ( two half lives or 80 days) 120 /2 = 60 g decays and 60 g remains left .
after three half lives or 120 days, 60/2 = 30g decay and 30 g of the isotope will be left.
The value of n is 1 because 523 divided by 10 = 52.3 and the only way to get 10 from 10n is if the value of n is 1
Answer:
480 milligrams
Step-by-step explanation:
92 pounds → 320 milligrams
138 pounds → 320/92 x 138 = 480 milligrams