Iodine-131 has a half life of 8 days, so half of it is gone every 8 days.
10 grams of iodine-131 is left for 24 days.
At 8 days: 10/2=5 grams left
At 16 days: 5/2=2.5 grams left
At 24 days: 2.5/2=1.25 grams left.
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Your mistake is that you stopped at 16 days.
I'm not sure but I had this question on a benchmark I think its the density of the wire you need to find the density or the mass I'm not sure but i do remember this question
Answer:
a) 4500 cycles b) 0.0667s c) 6.67s
Explanation:
a) 15 Hz= 15 cycles/ s
5 mins= 300s
15 cycles/s * 300s= 4500 cycles
b) Period= 1/ frequency
Period= 1/ 15 cycles/s
Period= 0.0667s
c) Period * number of revolutions= time
0.0667 * 100= 6.67s
I think it false. Sorry if i'm wrong.
