tion:In physics and chemistry, ionization energy (American English spelling) or ionisation energy (British English spelling) is the minimum amount of energy required to remove the most loosely bound electron of an ISOLATED neutral GASEOUS atom or molecule.[1] It is quantitatively expressed asIonization energy trends plotted against the atomic number. The ionization energy gradually increases from the alkali metals to the noble gases. The maximum ionization energy also DECREASES from the first to the last row in a given column, due to the increasing distance of the valence electron shell from the nucleus.X(g) + energy ⟶ X+(g) + e−where X is any atom or molecule, X+ is the ion with one electron removed, and e− is the removed electron.[2] This is generally an endothermic process. As a rule, the closer the outermost electrons to the nucleus of the atom, the higher the atom's ionization energy.The sciences of physics and chemistry use different units for ionization energy.[3] In physics, the unit is the amount of energy required to remove a SINGLE electron from a single atom or molecule, expressed as electronvolts. In chemistry, the unit is the amount of energy required for all of the atoms in a mole of substance to lose one electron each: molar ionization energy or approximately enthalpy, expressed as kilojoules per mole (kJ/mol) or kilocalories per mole (kcal/mol).[4]Comparison of ionization energies of atoms in the periodic table reveals two periodic trends which follow the rules of Coulombic attraction:[5]Ionization energy generally increases from left to right within a given period (that is, row).Ionization energy generally decreases from top to bottom in a given group (that is, column).please mark me as brainlist