Question

compare the 1st I.E of group 16,17and18 elements​

Answer 1

Group 16 elements have a lower value of first ionization enthalpy as compared to group 15 elements. As group 15 elements have half filled p-orbital due to which group 15 have got extra stability.｡◕‿◕｡

Answer 2

In physics and chemistry, ionization energy or ionisation energy, denoted Eᵢ, is the minimum amount of energy required to remove the most loosely bound electron, the valence electron, of an isolated neutral gaseous atom or molecule.