The graph of binding energy per nucleon `(overlineBE)` versus mass number (A) for various nuclei has been approximated as made up of two linear components as shown in figure. The slope of line for `0ltAlt56` is 0.16 and slope of line for `A56` is -0.012. the binding energy of `._(2)^(4)He` nucleus is 11 times the value predicted by the shown graph due to its very stable structure. Estimate the minimum mass number (A) of a nucleus for it to exhibit alpha decay.
