Which of the following species has the lowest first ionization enthalpy?

Which of the following has the lowest first ionization thalpy?

Which of the following species has the highest ionization potential

Which of the following elements has the lowest ionization potential ?

Which of the following group 14 element has the lowest first ionization enthalpy?

Which of the following elements has the highest first ionization potential?

Which of the following s-block metals has the lowest first ionisation energy?

Which of the following noble gases has the first ionization enthalpy which is almost identical to that of dioxygen?