Question

Investigate using liquid drop model, the β stability of the isobars 12753I and 12754Xe given that

12751Sb → β− +12752Te + 1.60 MeV

12755Cr → β+ +12754Xe + 1.06MeV

Answer 1

The liquid drop model gives the value of Z for the most stable isobar of mass number A by

Z0 = A/(2 + 0.015A2/3)

For A = 127, Z0 = 53.38, the nearest being Z = 53. Hence 12753I is stable. But 12754Xe is unstable against β+ decay or e− capture.