1. Credit: Oklahoma State Univ. Chem. Dep’t.

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

3. 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.)

4. Why are the ions formed by metal atoms smaller than the corresponding neutral atoms? Why are the ions formed by non-metal atoms larger than the corresponding neutral atoms?