PLEASE SOMEONE HELP ME ANSWER THIS i’m desperate:,,(

See detailed solution below

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