Answer:
The Time period required for decay of Iodine-125 to half of its value is 60 days .
Step-by-step explanation:
Given as :
The initial quantity of iodine-125 = 0.4 gram
The rate of decay = 1.15 %
Let The time period for decay = x day
The finial quantity after decay = half of initial quantity
I.e The finial quantity after decay = 0.2 gram
Now ,
The final quantity after decay = initial quantity ×
Or, 0.2 gm = 0.4 gm ×
or, =
Or, 0.5 =
Or, = 0.9885
Taking log both side
log ( ) = Log 0.9885
or, × log 0.5 = - 0.0050233
or, × ( - 0.301029 ) = - 0.0050233
or, x =
∴ x = 59.92 ≈ 60 days
Hence The Time period required for decay of Iodine-125 to half of its value is 60 days . Answer