Answer:0.75 milligrams will be present in 24 hours
Explanation:
Step 1
The formula for radioactive decay can be written as
N(t)=No (1/2)^(t/t 1/2)
where
No= The amount of the radioactive substance at time=0=milligrams
t 1/2= the half-life= 6 hours
t=24 hours
N(t) = the amount at time t
Step 2--- Solving
N(t)=No (1/2)^(t/t 1/2)
=N(t)=12 x ( 1/2) ^ (24/6)
= 12 x (1/2) ^4
= 12 x 0.0625
= 0.75 milligrams