What is the trend of ionisation enthalpy in a period?

Out of P^3-,  S^2- and Cl^- ions, which has the smallest value of ionic radius and why?

Among the elements Li, K, Ca, S and Kr, which one has the highest first ionisation enthalpy and which one has the lowest first ionisation enthalpy?

What is the relationship between the first ionisation enthaplies and metallic properties?

For each of the following pairs state which one has greater ionisation enthalpy:
(i) I, I^- (ii) Br, K.

Out of the following which has the smallest ionic 'Size and why: Li⁺, Na⁺, K⁺?

What is the trend of ionisation enthalpy in a group?

Which one out of Na⁺ and Cl^- is bigger in size and why?

Which one out of O and Se is bigger in size and why?

From amongst the following, choose the element with the lowest IE: Be, B and C.