The nuclei ${ }_{6} C^{13}$ and ${ }_{7} N^{14}$ can be described as
isotopes of nitrogen
isotopes of carbon
isobars
isotones
Isotopes are atoms having
Assertion $(A):$ Forces acting between proton-protn $\left(f_{p p}\right)$, proton-neutron $\left(f_{p p}\right)$ and neutron-neutron $\left(f_{n n}\right)$ are such that $f_{p p} < f_{p n}=f_{n n}$
Reason $(R):$ Electrostatic force of repulsion between two protons reduces net nuclear forces between them.
If the total binding energies of ${ }_1^2 H ,{ }_2^4 He ,{ }_{26}^{56} Fe$ and ${ }_{92}^{235} U$ nucleiare $2.22,28.3,492$ and $1786 MeV$ respectively, identify the most stable nucleus of the following.
The decay of a proton to neutron is :
In $_{88}R{a^{226}}$ nucleus, there are