The isotopes
Are all stable,while
Is radioactive.The mode of decay for
Is most likely to be
A)positron decay.
B)($\alpha$ decay.)
C)($\gamma$ decay.)
D)electron capture.
E)($\beta$ decay.)

Question

The isotopes 
Are all stable,while 
Is radioactive.The mode of decay for 
Is most likely to be
A)positron decay. 
B)($\alpha$ decay.) 
C)($\gamma$ decay.) 
D)electron capture. 
E)($\beta$ decay.)

Quizplus · Accepted Answer

The fact that an isotope is radioactive means that it is undergoing decay, and the options given are the different types of decay that can occur. Among these options, electron capture and positron decay require the presence of a nucleus that has too many protons relative to neutrons. However, the fact that all isotopes in this problem have more or less equal numbers of protons and neutrons (they are close to the line of stability on a nuclear chart) means that these types of decay are unlikely. Similarly, alpha decay requires a very heavy nucleus, and gamma decay involves the emission of a photon rather than a particle. That leaves beta decay as the most likely option, since it involves the conversion of a neutron into a proton (or vice versa) by the emission or capture of an electron. Since the isotope given is not a positron emitter, the best answer is beta decay.

The Isotopes Are All Stable,while Is Radioactive α\alphaα Decay) C)

The Isotopes
Are All Stable,while
Is Radioactive $\alpha$ Decay)
C)