Types of Bonding

There are two types of bonds: Ionic bonds Ionic bonds Covalent bonds Covalent bonds

IONIC BONDING

Ionic Bonding Occurs between a metal and a nonmetal Occurs between a metal and a nonmetal Ionic Bond - Electrons are transferred from one atom to the other Ionic Bond - Electrons are transferred from one atom to the other

Properties of Ionic Compounds Ionic compounds have high melting points (meaning they are very strong) Ionic compounds have high melting points (meaning they are very strong) Ionic compounds are also very brittle Ionic compounds are also very brittle Ionic compounds usually dissolve in water (these solutions are good conductors of electricity) Ionic compounds usually dissolve in water (these solutions are good conductors of electricity)

The Octet Rule Octet Rule – atoms tend to gain, lose, or share electrons in order to acquire a full set (8) valence electrons Octet Rule – atoms tend to gain, lose, or share electrons in order to acquire a full set (8) valence electrons Remember that is the goal of atoms to have the electron configuration of noble gases Remember that is the goal of atoms to have the electron configuration of noble gases

Lewis Dot Diagrams The valence electrons are the only ones that will participate in bonding so we will concentrate on those. The valence electrons are the only ones that will participate in bonding so we will concentrate on those. In Lewis Dot Diagrams we use dots to represent electrons around the symbol of an element to allow people to see how many valence electrons they have In Lewis Dot Diagrams we use dots to represent electrons around the symbol of an element to allow people to see how many valence electrons they have

Group 1A – 1 valence electron Group 1A – 1 valence electron Group 2A – 2 valence electrons Group 2A – 2 valence electrons Group 3A – 3 valence electrons Group 3A – 3 valence electrons Group 4A – 4 valence electrons Group 4A – 4 valence electrons Group 5A – 5 valence electrons Group 5A – 5 valence electrons Group 6A – 6 valence electrons Group 6A – 6 valence electrons Group 7A – 7 valence electrons Group 7A – 7 valence electrons Group 8A – 8 valence electrons Group 8A – 8 valence electrons

An Example: Carbon has 4 valence electrons: We use the dots to represent the valence electrons! C

Polyatomic Ions We have dealt with ions like Na +1 or Cl -1 …those are monatomic ions (ions consisting of only one atom). Another important group exists…polyatomic ions. They consist of more than one atom and still have either a positive or negative charge.