Answer:
See detailed solution below
Step-by-step explanation:
Now, let us solve each question step by step.
1) Given that;
N = amount of radioactive material at time t
No= amount of radioactive material originally present
t = time required for N amount of radioactive material to remain
t1/2= half life of the radioactive material
So,
N/No = (1/2)^t/t1/2
N/60 = (1/2)^22.8/3.8
N/60= (1/2)^6
N/60=1/64
64 N = 60
N = 60/64
N = 0.9 g
2) N/No = (1/2)^t/t1/2
N/8 = (1/2)^103.2/34.4
N/8 = (1/2)^3
N/8 = 1/8
8N = 8
N = 1 L
3) N/No = (1/2)^t/t1/2
50/No = (1/2)^18/6
50/No = (1/2)^3
50/No = 1/8
No = 50 * 8
No = 400 micrograms
4) N/No = (1/2)^t/t1/2
62.5/500 = (1/2)^26/t1/2
0.125 = (1/2)^26/t1/2
Since 0.125 = 1/8
1/8 = (1/2)^26/t1/2
(1/2)^3 = (1/2)^26/t1/2
Hence;
3 = 26/t1/2
t1/2 = 26/3
t1/2 = 8.7 hours