Home ยป If the 1st ionization energy of H atom is 13.6 eV, then the 2nd ionization energy of He atom is Atomic Structure MCQs If the 1st ionization energy of H atom is 13.6 eV, then the 2nd ionization energy of He atom is January 8, 2022 13 Views Q. If the 1st ionization energy of H atom is 13.6 eV, then the 2nd ionization energy of He atom is A. 27.2 eV B. 40.8 eV C. 54.4 eV D. 108.8 eV Answer: 54.4 eV