Kinds of Bonds

Chemical Bonds are formed when atoms gain, lose, or share electrons

ion An ion is a charged particle – it has a different number of electrons than protons ionic bond An ionic bond is the attractive force between the opposite charges of the ions Ionic Bonding

Types of Ions A cation has a positive charge An anion has a negative charge

Ionic Bond Formation crystals Ionic substances form crystals because they connect to all of the neighboring opposite charges.

Properties of Ionic Compounds Hard Hard and brittle Solid Solid at room temperature high boiling Have very high melting points and boiling points

Properties of Ionic Compounds electricity Can conduct electricity if heated to a liquid state dissolvedwater Can conduct electricity if dissolved in water or some other solvent

NaCl (salt) NaF (in toothpaste) NaOH (Drano) Examples

Covalent Bonding covalent share A covalent bond forms when atoms share electrons singleone multiple A single bond contains one pair of electrons, but atoms can share multiple pairs of electrons.

Covalent Bonding Connect lone single dots of Lewis structure to show covalent bonds

hard and brittle flexible Some are hard and brittle but less than ionic; Others are flexible, or soft and mushy. solid, liquid or gas Can be solid, liquid or gas at room temperature. boiling points Their boiling points vary from - 253°C to over 4800°C. Covalent Properties

notelectricity Most do not conduct electricity regardless of their state of matter. don’t When dissolved in a solvent, they don’t conduct electricity. Covalent Properties

C 12 H 22 O 11 (Sugar) NH 3 (Ammonia) C 3 H 8 (Propane) Examples

Metallic Bonds metal A metallic bond involves an attraction between metal atoms that loosely involves many electrons. Sea of Electrons We call this a “Sea of Electrons”

Metallic Bonds heat electricity Many electrons are moving around the metal which makes the metal highly conductive to heat and electricity.

Oxidation/“Magic” Numbers 0 or 8 Atoms gain / lose electrons to form an ionic bond to get to the magic number of 0 or 8 how many Oxidation is how many electrons you will gain or lose to get to 0 or 8. (basically it’s the charge!!!)

Oxidation/“Magic” Numbers

Oxidation Numbers negative If an atom gains electrons, it has a negative oxidation number. positive If an atom loses electrons, it has a positive oxidation number.

Oxidation Numbers For Bonding: Oxidation means CHARGE!!!!!!

What is the oxidation number (charge) of: HBa SF NaSi

group charge A polyatomic ion is a covalently bonded group of atoms with either a positive or negative charge We will revisit this later, but understand what it is.