Answer
$\therefore \text{Element having atomic number 34 is selenium}$ (i.e $\textbf{Se}$ )
Work Step by Step
From the electronic configuration $1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^4$
Atomic Number of Given element is $\textbf{34}$
So, Element having atomic number 34 is selenium (i.e $\textbf{Se}$ )