The mass of a radioactive substance follows a continuous exponential decay model. a sample of this radioactive substance has an initial mass of 9575 kg and decreases continuously at a relative rate of 12% per day. find the mass of the sample after five days.

Exponential decay is a very common process especially when we are talking about radioactive materials. So, there is already a common formula for this type of behavior which is written below:

A = Pe^-rt
where
A is the amount left after time t
P is the initial amount at t=0
r is the rate

Substituting the values,
A = (9575 kg)(e^-0.12*5)
A = 5,254.87 kg

It is called a neutralization reaction