Predict the mode of decay for Mn-59.

Question

a. beta decay <--
b. positron emission
c. electron capture
d. Mn-59 is stable

I was wondering how it was a. and not the others through an explanation? Thanks!

Answer 1

This you tube has a rather good explanation.
https://www.youtube.com/watch?v=G_83ES6ceo4

N = 34 and Z = 25 and N/Z = about 1.36. For elements in the 20-40 Z you want N/Z to be 1.25 so we need to convert neutrons to protons which means emission of a beta particle.