Answer:
73.5%
Step-by-step explanation:
The question is incomplete, the complete question is shown in the image attached.
Half life (t1/2) = 9 days
Time taken (t) = 4 days
From;
0.693/t1/2 = 2.303/t log (No/N)
Substituting values;
0.693/9 = 2.303/4 log(No/N)
0.693/9 × 4/2.303= log(No/N)
2.772/20.727= log(No/N)
Antilog (2.772/20.727)=No/N
1.36 = No/N
Therefore;
N/No = (1.36)^-1
N/No = 0.735
Percentage remaining after 4 days= 0.735× 100= 73.5%
