Credit: OklahomaState Univ. Chem.Dep’t.

Ionization Energy = the amount of energy (measured in kiloJoules / mole) needed to removethe 1st electron from an atom: atom + energy ion+ + e-

Electronegativity = Atomic Selfishness, the ability to attract electrons toward the atom,usually within a chemical bond. How hard an atom pulls on its (shared) electrons.• If the difference in electronegativities between 2 atoms is < 0.4, a non-polar covalent bond results. The electrons are shared roughly equally.• If the difference in electronegativities is < 1.7, a polar-covalent bond results (unequal sharing.)• If the difference in electronegativities is > 1.7, an ionic bond results (transfer of e- has taken place.)

Why are the ions formed by metal atoms smaller than the correspondingneutral atoms?

Why are the ions formed by non-metal atoms larger than the correspondingneutral atoms?