Question

The rate of decay (dP/dt) of a population of radioactive parent atoms __________ over time.

1) increases
2) decreases
3) stays constant
4) varies randomly

Answer 1

The rate of decay (dP/dt) of a population of radioactive parent atoms decreases over time.

Step-by-step explanation:

The rate of decay (dP/dt) of a population of radioactive parent atoms decreases over time.

In radioactive decay, the number of atoms of the radioactive isotope decreases with time as their nuclei decay to nuclei of a more stable isotope. The rate of decay, or activity, is defined as the decrease in the number of the radioisotope's nuclei per unit time. This activity decreases exponentially with time.

For example, in a sample of 1 million atoms of a radioactive isotope, 500,000 atoms are expected to decay over a certain period of time.