B. Ionic size 1. Ele in a group form ions of same charge. The energy needed to remove one e- from an atom. Must also consider where the e- are being removed . D. Electron affinity 1.
Electronegativity is a measure of the ability of an atom to attract e- in a chem bond.
The most en element, F, is arbitrarily assigned an en value of 4. They contain the from 0 to 2 e- in the highest occupied E level.