Answer:
A half life of element is 8.07 days
B iodine 131
C check equation in attached image
Explanation:
80/2 =40
40/2=20
20/2=10
10/2=5
5/2=2.5
After 5 half lives it becomes 2.5 kg
n is the number of half-lives that pass in a given period of time
n= period of time/ half-life
Half life =period of time / n
Half life = 40.35/5= 8.07 days
odine-131 → xenon-131 + beta particle
