From the calculations and the information taht we can glean from the question, the mass of the antibiotic left after 12 hours is 8.59 mg.
The term decay has to do with the breakdown of a chemical substance. Since the decay depends only on the initial amount of the drug the process folows the first order kinetics.
Hence;
N = amount left at time t
No= amount initual present
t = time taken
t1/2 = half life of the drug
N/No = (1/2)^t/t1/2
N/550 = (1/2)^12/2
N = 550[(1/2)^12/2]
N = 8.59 mg
Learn more about exponential decay: https://brainly.com/question/2193799
