For hydrogen atom, energy of an electron in first excited state is $-3.4 \mathrm{~eV}, \mathrm{K} . \mathrm{E}$. of the same electron of hydrogen atom is $x \mathrm{~eV}$. Value of $x$ is _________ $\times 10^{-1} \mathrm{~eV}$. (Nearest integer)