Q 12-13-065JEE MainJEE Main 2023 (31 Jan, Shift 1)Easy
A free neutron decays into a proton but a free proton does not decay into neutron. This is because
Answer: (D) neutron has larger rest mass than proton
A free particle can decay only if the products have less total rest mass energy. The neutron is heavier than the proton, so $n\to p+e^-+\bar\nu$ releases energy, while a free proton cannot turn into a heavier neutron.
Solution by Sreeraj P, M.Sc Physics