Which of the following statements about radioactive decay is true?
a. radioactive decay is the rate at which new atoms form.
b. During radioactive decay, atoms break down, releasing, particles or energy.
c. the rate of decay of a radioactive element cannot be approximated.
d. the number of radioactive atoms in a sample will always remain constant.

Which of the following terms refers to the time it takes for one-half of the radioactive atoms in a sample of a radioactive element to decay?
a. relative age.
b. absolute age.
c. potassium-argon date
d. half-life