In order to remove one electron from a 3S orbital of gaseous sodium atom, about 496KJMol-1 of energy is required. This energy is referred to as

Answer Details

The energy required to remove an electron from an atom is called ionization energy. In this case, the question specifically states that the energy required to remove one electron from a 3S orbital of gaseous sodium atom is 496 kJ/mol. Therefore, the correct answer is ionization energy. Ionization energy is a measure of how strongly an atom holds onto its electrons. The higher the ionization energy, the more difficult it is to remove an electron from the atom. The ionization energy is often used to describe the reactivity of an element and its ability to form chemical bonds.