A nuclide 1 is said to be the mirror isobar of nuclide 2 if Z1 = N2 and Z2 = N1. (a) What nuclide is a mirror isobar of 2311Na2311Na? (b) Which nuclide out of the two mirror isobars have greater binding energy and why?

:NEETprep Answer:
Hint: The binding energy of a nucleus depends on the no. of nucleons.
Step 1: Find the mirror isobars.
(a) According to question, a nuclide 1 is said to be mirror isobar of nuclide 2, if Z1 = N2 and Z2 = N1
Now in 11Na23, Z1=11, N1=23-11=12Now in 11Na23, Z1=11, N1=2311=12
 Mirror isobar of 11Na23 is 12Mg23, for which Z2=12=N1 and N2=23-12=11=Z1 Mirror isobar of 11Na23 is 12Mg23, for which Z2=12=N1 and N2=2312=11=Z1
Step 2: Find the no. of nucleons in each isobar.
(b) As2312Mg2312Mg contains an even number of protons (12) against 2311Na2311Na which has an odd number of protons (11), therefore 2312Mg2312Mg has greater binding energy than11Na2311Na23.