The Environmental Protection Agency and health officials nationwide are concerned about the levels of radon gas in homes. The half-life of the radon-222 isotope is 3.8 days. If a sample of gas taken from a basement contains 2.1 µg of radon-222, how much radon will remain in the sample after 4.94 days? Answer in units of µg.

The amount left after 4.94 days is

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) to calculate amount left after 4.94 days

The amount left after 4.94 days is