Question

Regarding radioactivity:

a. Decay of radionuclides with a neutron excess produces a daughter nucleus with a higher atomic number

b. The rate of decay can be increased by heating the radionuclide

c. Isomers have the same half-life

d. Decay of radionuclides with a neutron deficit produces a daughter nucleus with a lower atomic number

e. Positron annihilation results in energy being converted to mass

Answer 1

a. True. This is known as beta-negative (b) decay and results in the conversion of a neutron to a proton, therefore increasing atomic number.

b. False. The rate of decay is dependent on the characteristic of the radionuclide and is unaffected by factors such as heat or chemical reactions.

c. False. Isomers have differing half-life and energy states, but the same atomic and mass numbers.

d. True. This can occur either by beta-positive (b+) decay or K-electron capture, both of which result in the reduction of the number of protons and therefore atomic number.

e. False. Positrons collide with negative beta particles resulting in the two masses being converted to energy.