1. Ionic compounds
made up of positive and negative ions, but overall neutral
Consist of a metal and nonmetal
Also can include polyatomic ions which is a charged compound
Crystalline solids at room temperature
Strong bonds due to attraction of neighbor ions and reduction of repulsions
NaCl has a melting point of 8000C!

2. Ionic bonds Opposite charges of anions and cations attract each other
one or more atoms lose electrons and one or more atoms gain those electrons
Criss-cross the charges as new subscripts
Simplify subscripts by common denominator if possible

3. Ionic Bond Examples Sodium forms Na1+ Chlorine forms Cl1-
sodium (Na) and Chlorine (Cl) react to form sodium chloride (NaCl, aka table salt)
Sodium forms Na1+
Chlorine forms Cl1-
Na1++Cl1-  Na1Cl1  NaCl

4. Ionic bond example #2
Aluminum (Al) and Bromine (Br) react to form Aluminum bromide (AlBr3)
Aluminum forms Al3+
Bromine forms Br1-
Al3++Br1-  Al1Br3  AlBr3

5. Metallic Bonds
Closely packed cations and loosely held valence electrons
Think sea of valence electrons for pure metal (mobile and drifting free)
Think fruit at a grocery store
Good conductors of electric current (electrons moving freely)
Metal can be shaped (pushed into wire form without breaking)

6. Alloys
Combination of two or more elements with at least one being a metal
Superior properties of individual elements
Harder and more durable, but easier to shape
Ex bronze, sterling silver