The ionization enthalpy of hydrogen atom is 1.312×10⁶ j mol-1. The energy required to excite the electron in the atom from n=1 to n=2 is:
A. 8.51×10⁵ J mol-1
B. 6.56×10⁵ J mol-1
C. 7.56×10⁵ J mol-1
D. 9.84×10⁵ J mol-1