Types of Bonds

5.1Amole

Chemical Bonding When two or more atoms join a bond is

formed

It will not fall apart unless enough energy is added to break the bond

The type of bond determines certain properties of the compounds they create

Why do atoms bond? Octet Rule: Atoms tend to gain, lose, or share

electrons so as to have 8 electrons in their outermost shell (except for H and He)

Types of Bonds There are three main types of

bonds:

Ionic Bond

Covalent Bond

Metallic Bond

Learning Check: When two or more atoms join, a _________

forms.Bond

How many electrons do most atoms want in their outer shells?

8

What are the three types of bonds?Ionic, Covalent, and Metallic

IONIC BONDbond formed between

two ions by the transfer of electrons

Ionic Bonds Form between metals and nonmetals

Involves the transfer of electrons

The metal gives away electron(s) becoming a positive ion

The nonmetal gains electron(s) becoming a negative ion

The charged atoms are held together because the positive and negative forces are attracted to one another

Ionic bond – electron from Na is transferred to Cl, this causes a charge imbalance in each atom. The Na becomes (Na+) and the Cl becomes (Cl-), charged particles or ions.

Ionic Bonds: One Big Greedy Thief Dog!

Properties of Ionic Bonds Network solids

High melting and boiling points

Conduct electricity when melted

Many soluble in water but not in nonpolar liquid

Learning Check: When a bond is formed by the transfer of

electrons, a __________ bond is formed.Ionic

These bonds form between…Metals and nonmetals

The metals lose electrons to the nonmetals to create positive and negative ________.

Ions

COVALENT BOND

bond formed by the sharing

of electrons

Covalent Bonds Form between nonmetals

Involves the sharing of electrons

The nonmetals share one or more pairs of electrons to have a full octet

Two types: polar and nonpolar

Two Types: Determined by how electrons are

shared

Based on electronegativity

Shared evenly = Nonpolar

Shared unevenly = Polar

Non polar Covalent Bonds when electrons are shared equally H2 or Cl2

Oxygen Atom Oxygen Atom

Oxygen Molecule (O2)

Nonpolar Covalent Bonds: Evenly matched, but willing to share.

Polar Covalent Bonds when electrons are shared but

shared unequally H2O

Polar Covalent Bonds: Unevenly matched, but willing to share.

Properties of Covalent Bonds Gases, liquids, or solids

Low melting and boiling points

Poor electrical conductors in all phases

Many soluble in nonpolar liquids but not in water

Learning Check: When a bond is formed by the sharing of

electrons, a __________ bond is formed.Covalent

These bonds form between…Nonmetals

When atoms have different electronegativities, and share electrons unevenly, a ________ molecule is formed.

Polar

METALLIC BONDbond found in metals; holds

metal atoms together

very strongly

Metallic Bonds Form between metals

Involves the overlapping of outer energy levels

Attraction between one atom’s nucleus and a neighboring atom's electrons packs the atoms closely together

Allows electrons to move freely from one atom to another.

Metallic Bonds: Mellow dogs with plenty of bones to go

around.

Properties of Metallic Bonds Form alloys

Examples: steel, brass, bronze and pewter

Metals conduct electricity well do to the freedom of the electrons to move.

Metals are flexible because the atoms can slide past each other without their bonds breaking.

Identifying Types of Bonds

1. Look at the chemical formula2. Identify the elements in the compound3. Determine if the elements are metals or

nonmetals (using a periodic table)4. Metal – Metal = Metallic5. Metal – Nonmetal = Ionic6. Nonmetal -- Nonmetal = Covalent

1. Polar Covalent = different atoms/elements2. Nonpolar Covalent = same atoms/elements

Remember: Metals are on the left of the periodic table, and nonmetals are on the right.

Learning Check:Identify the type of bond present in each compound:

CH4

○ Carbon = Nonmetal○ Hydrogen = Nonmetal○ Covalent Bond (polar)

LiBr○ Lithium = Metal○ Bromine = Nonmetal○ Ionic Bond

FeCl3○ Iron = Metal○ Chlorine = Nonmetal○ Ionic Bond

O2

○ Oxygen = Nonmetal○ Oxygen = Nonmetal○ Covalent Bond (nonpolar)

Polyatomic Ions Compounds that contain polyatomic ions contain both ionic

and covalent bonds

Involves groups of covalently bonded atoms that have either lost or gained electrons.

  Parenthesis group the atoms of a polyatomic ion to

remind you that they act as one ion.

Pg. 158 contains a list of many common Polyatomic Ions.

Learning Check:Identify the type of bond present in each compound:

MgCl2○ Magnesium = Metal○ Chlorine = Nonmetal○ Ionic Bond

NH4Cl○ Ammonium = Polyatomic Ion○ Chlorine = Nonmetal○ Both; Ionic and Covalent

NaOH○ Sodium = Metal○ Hydroxide = Polyatomic Ion○ Both; Ionic and Covalent

NO2

○ Nitrogen = Nonmetal○ Oxygen = Nonmetal○ Covalent Bond (polar)