Question: The decay of a proton to neutron is :
(1) not possible as proton mass is less than the neutron mass
(2) possible only inside the nucleus
(3) not possible but neutron to proton conversion is possible
(4) always possible as it is associated only with $\beta^{+}$decay
Correct Option: , 2
Solution:
(2)
It is possible only inside the nucleus and not otherwise.
