1. Why Francium is the biggest element with the lowest IE and EN
Francium has seven valence shells which makes it the biggest element. Since it is so big, it takes more energy to get rid of an electron therefore it has the lowest ionization energy.
2. Why Helium is the smallest element with the highest IE
It has one shell so it is harder to remove an electron from the tight fitted shell. It takes more energy to remove an electron from a small atom.
3. Why Noble Gases don't have EN values
Noble Gases have full valence shells so they do not gain electrons.
4. Why Fluorine has the highest EN
Fluorine has the the highest electronegativity because it is the smallest element in the Halogens family so it has the most attraction to electrons.
