Ions and Ionic Bonds

Ion = Atom that has lost or gained electrons; has a charge (+ or -) Review: Ion = Atom that has lost or gained electrons; has a charge (+ or -) Atoms that Lose electrons Have a positive charge = +, 2+, 3+, etc. Called cations (“Cat Pos”) Atoms that Gain electrons Have a negative charge = -, 2-, 3-, etc. Called anions

Electrons are transferred Chemical bonds Attractive force that holds atoms or ions together Ionic Bond bond formed by the attraction between oppositely charged ions There is an electrostatic attraction between the ions Electrons are transferred Example: Na and Cl Cl takes an electron from Na Cl becomes Cl- Na becomes Na+ Na+ is attracted to Cl- Form ionic compound NaCl

Ionic bonds occur between a metal and a nonmetal Metals on left side of Periodic Table Nonmetals on right side of Periodic Table Most ionic compounds are called salts Example: Lithium combines with Chlorine to become LiCl Li has 1 valence electron (has 1 extra) Cl has 7 valence electrons (needs 1) Cl takes Li extra valence electron Cl becomes Cl- Li becomes Li+ Li+ is attracted to Cl- and form an ionic bond LiCl is the ionic compound that is formed

Li Cl Li Cl Li O Li O Li Li - Li+ + Cl- = LiCl 2 Li+ + O2- = Li2O Lithium + Chlorine - + Li Cl Li Cl Li+ + Cl- = LiCl Lithium + Oxygen + 2- Li O Li O + 2 Li+ + O2- = Li2O Li Li