The ionization energy of hydrogen atom is -13.6eV. The energy required to excite the electron in a hydrogen atom from the ground state to the first excited state is (Avogadro's constant = 6.022 × 1023):
(1) 1.69x 10-20J
(2) 1.69x 10-23J
(3) 1.69x 10-23J
(4) 1.69x 10-25J
Ans: 1.69x 10-23J