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Some “Big” Questions Why do some ions have specific charges in ionic compounds? Why are some substances solids, some liquids, and some gases at the same conditions of temperature and pressure?

The Answer to Life, the Universe, and Everything… The Second Law: Increase in Entropy of The Universe

Overall goal: Atomic Structure Chemical Bonding 3D Molecular Structure Molecular Properties

Clicker Question Consider different “sodium particles” (atom or ions) in separate evacuated containers. Which of the following sodium species is lowest in energy? a) Na b) Na+ c) Na2+ d) Na e) Na2

Clicker Question Consider different “oxygen particles” (atom or ions) in separate evacuated containers. Which of the following oxygen species is lowest in energy? a) O b) O+ c) O2+ d) O e) O2

Clicker Question Consider different “oxygen particles” (atom or ions) in separate evacuated containers. Which of the following oxygen species is second lowest in energy? a) O b) O+ c) O2+ d) O e) O2

Clicker Question Consider different “sodium particles” (atom or ions) in separate evacuated containers. Which of the following sodium species is lowest in energy? a) Na b) Na+ c) Na2+ d) Na e) Na2

Clicker Question Consider different “oxygen particles” (atom or ions) in separate evacuated containers. Which of the following oxygen species is lowest in energy? a) O b) O+ c) O2+ d) O e) O2

Clicker Question Consider different “oxygen particles” (atom or ions) in separate evacuated containers. Which of the following oxygen species is second lowest in energy? a) O b) O+ c) O2+ d) O e) O2

Arranged by Reactivity

Four Trends to Understand Atomic radius Ionization Energy Energy required to remove an electron from a gaseous atom or ion. Electron Affinity Energy change associated with the addition of an electron to a gaseous atom or ion. Electronegativity Ability of an atom in a molecule to attract shared electrons to itself.