Class Starter1. What is the chemical symbol for

silicon?2. How many electrons does silicon

have?3. How many valence electrons does

silicon have?

Chemical Bonding

Chapter 13

3 Types of Bonds1. Ionic An Ionic Bond is a chemical

bond resulting from the TRANSFER of electrons from one bonding atom to another Between metals and nonmetals

3 Types of Bonds2. Covalent A covalent bond is a

chemical bond resulting from SHARING of electrons between 2 bonding atoms. Between nonmetals

3 Types of Bonds3. Metallic A metallic bond occurs

between metals. A metal consists of positive ions surrounded by a “sea” of mobile electrons.

Why Bond?

Forming of a bond is like marriage…more stable.

The breaking of a bond relates to a divorce. .. Less stable.

Octet Rule•Rule that states that atoms tend to gain, lose, or share electrons so that each atom has full outermost energy level which is typically 8 electrons.

Valence electrons in ionic bonds

1 2 3 4 5 6 7

If an element has 3 or less valence electrons, it will lose them.

If an element has 5 or more valence electrons, it will gain enough to fill outer level.

Valence electrons in ionic bonds

1 2 3 4 5 6 7

If an element has 4 valence electrons, it can gain or lose valence electrons depending on what it “needs” to do.

Practice How many electrons do the following

elements want?Carbon? Nitrogen?

Lithium?C would like to N would like toLi would like to

Gain or Lose 4 electronsGain 3 electronsLose 1 electrons

Ions• When atoms gain or lose electrons, they

are called ions.

Ions• If an element loses electrons then it

becomes positively-charged and is called a cation

• Metals are always the cation.

• It is very easy to lose these electrons and become positively charged.

Ions• If an element gains electrons then it

becomes negatively-charged and is called an anion

• Nonmetals are always the anion.• It is very easy to gain enough electrons to fill

the outer energy level and become negatively charged.

Sodium Atom Sodium Ion

Formation of Sodium Ion

2, 8, 1Will sodium gain or lose its valence e- ? LOSE

11 p+

11 e- - 1 e- = 10 e-

1 +

Na+

Boron Atom Boron Ion

Formation of Boron Ion

2, 3Will boron gain or lose its valence e- ? LOSE

5 p+

5 e- - 3 e- = 2 e-

3 +

B+3

Sulfur Atom Sulfur Ion

Formation of Sulfur Ion

2, 8, 6Will sulfur gain or lose its valence e- ? Gain

16 p+

16 e- + 2 e- = 18 e-

2 -

S-2

Fluorine Atom Fluorine Ion

Formation of Fluorine Ion

2, 7Will fluorine gain or lose its valence e- ? Gain

9 p+

9 e- + 1 e- = 10 e-

1 -

F-1

Ionic Bonding• Occurs when two or more ions combine to

form an electrically-neutral compound.

Create a compound between sodium and fluorine.

Na+1 F-1 NaF

Ionic BondingCreate a compound between sodium and sulfur.

Na+1 S-2

Na2S

Na+1 Na+1 S-2

Ionic BondingCreate a compound between Magnesium and Chlorine.

Mg+2 Cl-1

MgCl2

Mg+2 Cl-1 Cl-1

Transition Metal IonsCobalt Co+2 Mercury Hg+2

Iron (II) Fe+2 Nickel Ni+2

Iron (III) Fe+3 Tin Sn+2

Lead (II) Pb+2 Silver Ag+1

Lead (IV) Pb+4 Zinc Zn+2

Manganese Mn+2

Class Starter1. Will bromine gain or lose electrons?

How many?2. Will magnesium gain or lose

electrons? How many?3. What “charge” will bromine obtain?4. What “charge” will magnesium obtain?5. Make a compound between bromine

and magnesium.

Class Starter1. Will aluminum gain or lose electrons?

How many?2. Will oxygen gain or lose electrons?

How many?3. What “charge” will aluminum obtain?4. What “charge” will oxygen obtain?5. Make an ionic compound between

aluminum and oxygen.

Class Starter1. Will boron gain or lose electrons? How

many?2. Will carbon gain or lose electrons?

How many?3. What “charge” will boron obtain?4. What “charge” will carbon obtain?5. Make an ionic compound between

boron and carbon.

Naming Ionic Compounds• Ionic compounds all have two-word

names• The first word in the name is the same as

the name of the cation (positive ion)

• The second word in the name is the anion (negative ion) with the ending “-ide”.

Ex. Chlorine Chloride or Oxygen Oxide

Practice Naming Ionic Compounds• Sodium and Fluorine

• Sodium and Sulfur

• Magnesium and Chlorine

Sodium Fluoride

Sodium Sulfide

Magnesium Chloride

Polyatomic Ions• There are some ions that are made

up of more than one type of atom, these are called polyatomic ions.

Practice Naming Ionic Compounds

• Na2CO3 -- • CaSO4 --

• KBr --

• NH4F --

Sodium Carbonate

Calcium Sulfate

Potassium Bromide

Ammonium Fluoride