Explanation:
In \(^{6}_{3}Li\), the atomic number is 3 and mass number is 6. Hence, there are 3 protons and 3 neutrons in this element.
Whereas in \(^{9}_{3}Li\),the atomic number is 3 and mass number is 9. Hence, there are 3 protons and 6 neutrons.
And, it is known that for lighter elements the ration for neutron to proton should be 1:1. Whereas for heavier elements the ratio for neutron to proton should be 3:2.
Hence, in \(^{6}_{3}Li\) the ratio for neutron to proton is 1:1. So, it is more stable in nature.
Thus, we can conclude that \(^{6}_{3}Li\) is expected to be more stable.
