Doctors can use radioactive chemicals to treat some forms of cancer. The half life of a certain chemical is 7 days. A patient receives a treatment of 16 millicuries of the chemical. (A millicurie is a unit of radioactivity.) How much of the chemical remains in the patient 14 days later?
To find out how much of the chemical remains in the patient 14 days later, we need to determine how many half-lives have passed and then calculate the remaining amount.
Since the half-life of the chemical is 7 days, after 7 days, half of the chemical will remain. Thus, after the first half-life, the patient will have 16/2 = <<16/2=8>>8 millicuries left.
After another 7 days (14 days total), another half-life will have passed, leaving half of the previous amount. So, the patient will have 8/2 = <<8/2=4>>4 millicuries left.
Therefore, 4 millicuries of the chemical will remain in the patient 14 days later.