Radioactive gold-198 is used in the diagnosis of liver problems. The half-life of this isotope is 2.7 days. If you begin with a sample of 8.6 mg of the isotope, how much of this sample remains after 1.4 days?

6.1 mg

Explanation:

Expression for rate law for first order kinetics is given by:

where,

k = rate constant

t = age of sample

a = let initial amount of the reactant

a - x = amount left after decay process  

a) for completion of half life:

Half life is the amount of time taken by a radioactive material to decay to half of its original value.

b) sample remains after 1.4 days

The sample remains after 1.4 days is 6.1 mg