Question

what is the energy required to remove an electron from an atom in the gaseous state called?

nuclear energy
electronegative energy
ionization energy
shielding energy

Explanation:

Nuclear energy is related to the nucleus of an atom, involving processes like fission or fusion. Electronegative energy is not a standard term in chemistry; electronegativity is a measure of an atom's ability to attract electrons in a chemical bond. Shielding energy is not a commonly used term in this context; shielding effect refers to the reduction in attraction between the nucleus and outer - shell electrons due to inner - shell electrons. Ionization energy is defined as the energy required to remove an electron from an atom in the gaseous state.

Answer:

ionization energy