DAILY QUESTION October 16, Ionic bonds are formed between ____________ charged ions.

Agenda10/16/08 Daily Question Chapter 5 Section 2 Notes Assignments: 1. Ch 5 Sections 1 and 2 Review Worksheet due 10/17

Bonds Valence electrons interact Atoms join to form bonds so that each atom has a stable electron configuration Positively charged nucleus attracts negatively charged valence electrons Bond will not break until enough energy is added

Three Types of Bonds Ionic bonds Metallic bonds Covalent bonds

Ionic bonds Formed between oppositely charged ions Metal elements form positively charged ions Nonmetal elements form negatively charged ions

Ionic bonds Atoms transfer electrons to form ions Both ions that form usually have stable electron configurations The oppositely charged ions attract each other and form an ionic bond

Ionic compounds Networks are formed Neutral compound can be in different ratios When melted or dissolved in water, ionic compounds can conduct electricity

Metallic bonds Attraction between one atom’s nucleus and a neighboring atom’s electrons packs the atoms close together This close packing causes the outermost energy levels of the atoms to overlap Electrons are free to move from atom to atom –Explains why they are good conductors and flexible

Covalent bonds Formed between non-metal atoms Atoms share electrons One line = 2 electrons shared –Chlorine Two lines = 4 electrons shared –Oxygen Three lines = 6 electrons shared –Nitrogen

Covalent bonds Nonpolar covalent bonds: electrons are shared equally Polar covalent bonds: unequal sharing of electrons

Polyatomic Ions Groups of covalently bonded atoms that have either lost or gained electrons. –OH - (Figure 17 in book) Parentheses group the atoms of a polyatomic ion – (NH 4 ) + The ion’s charge applies to the whole ion

Polyatomic Anions General rules: –-ate ending: 1 more oxygen atom –-ite ending: 1 less oxygen atom Table 3 in book lists several common polyatomic anions