The total energy of an electron in tire first excited state of hydrogen is about -3.4 eV. Its kinetic energy in this state is

Kinetic energy of electronK=Ze28πε0rPotential energy of electron U=−14πε0Ze2r∴Total energyE=K+U=Ze28πεor−Ze24πεoror  E=−Ze28πεoror  E=−Kor  K=−E=−−3.4=3.4eV