Answer
$C^{14}_6$
Work Step by Step
We calculate the atomic number as
$Z=7+(-1)+0=6$, this means that the required element is carbon C.
The atomic mass is
$A=14+0=14$
Thus, the complete nuclear reaction is
$C^{14}_6\rightarrow N^{14}_6+e^{-}+v^{-}$