The first ionization energies (kJ/mol) of hydrogen (H), nitrogen (N), fluorine (F), and oxygen (O) are 1,312, 1,402, 1,742, and 1,314, respectively. From which electrically neutral atom does it take the least energy to remove the first electron?
Ionization energy is a chemical property of the substance or in this case atom which refers to the amount of energy that is needed in order to remove the most loosely bounded electrons to the atom. This would mean that the chemical with the least ionization energy will be the answer.
From the choices given, it can then be concluded that it will take the least energy for hydrogen.
