Question

A sample of the radioisotope potassium-40 is crushed to increase its surface area. The temperature of the sample is then lowered 25°C. What affect do these changes have on the rate of nuclear decay?

A.)The decay rate doubles
B.)The decay rate decreases by half
C.)The decay rate increases by half
D.)The decay rate does not change

Answer 1

The answer should be D.)The decay rate does not change
A radioisotope is not stable and will undergo a nuclear decay that will continually decrease its mass. Unlike a chemical reaction, the rate of nuclear decay is not influenced by the temperature of the surface area. So, increases in surface area and decreased temperature will not have any effect.