Ionic Bonding

&

Covalent Bonding

Ionic Bonding• Ionic Bonding – TRANSFER of electrons

Metals + Nonmetals = Ionic Bond

Ionic Bonding- Transfer of Electrons

11 P

12 N

17 P

18 N

Sodium (Na)

METAL

Chlorine (Cl)

NONMETAL

BEFORE BONDINGNeutral Atom – Equal number of

protons and electrons

11 P

12 N

Sodium (Na)

11 Protons (+)

- 11 Electrons (-)

-----

0 (NO CHARGE)

11 P

12 N

Sodium (Na) ION

After Bonding…..Atom loses or gains electrons,

resulting in an ion with a charge

X 11 Protons (+)

- 10 Electrons (-)

-----

1+ (POSTIVE CHARGE)

MORE

LOSE ELECTRONS Positive Charge (+)

17 P

18 N

Chlorine (Cl)

BEFORE BONDINGNeutral Atom – Equal number of protons

and electrons

17 Protons (+)

- 17 Electrons (-)

-----

0 (NO CHARGE)

17 P

18 N

Chlorine (Cl)

17 Protons (+)

- 18 Electrons (-)

-----

1- (NO CHARGE)

After Bonding…..Atom loses or gains electrons, resulting in

an ion with a charge

GAIN ELECTRONS Negative Charge (-)

MORE

Valence Electrons

How many valence electrons does sodium (Na) have?

How many valence electrons does chlorine (Cl) have?

Lets look……

11 P

12 N

17 P

18 N

Electron Dot Diagram- symbol of element and valence electrons

When sodium LOSES an electron to chlorine, it becomes a sodium ion with a +1 charge.

When chlorine GAINS an electron from sodium, it becomes a chlorine ion with a -1 charge.

How many valence electrons does lithium (Li) have?

How many valence electrons does oxygen (O) have?

Valence Electrons

Let’s Look…..

Are the atoms stable after the electron transfer? Why? Or Why not?

NO! the oxygen atom needs to gain 2 electrons to have a complete outer energy level!

Let’s Look…..

2 lithium atoms are needed to complete the ionic bond!

-2 Charge

+1 Charge

+1 Charge

Question?

How would you write the chemical formula?

+1 Charge

+1 Charge

-2 Charge

Li2O

Let’s Practice…..

Directions: Show the ionic bond and charge formed between the following compounds, using the electron dot diagram!

1. CaO

2. KI

3. MgCl

Covalent Bonding = Sharing of electrons

Nonmetal + Nonmetal = Covalent Bond

Covalent Bonds: SHARING of electrons

Electrons can be shared: EQUALLY between nonmetal atoms

= NONPOLAR covalent bond

UNEQUALLY between nonmetal atoms = POLAR covalent bond

Valence Electrons

• How many valence electrons does nitrogen have (N)?

How many electrons would two nitrogen atoms have to share to become stable?

NONPOLAR Covalent Bond- EQUAL SHARING of electrons between

NONMETALS

Each PAIR of electrons represents a bond.

How many bonds are there between the two nitrogen atoms?

Valence Electrons

• How many valence electrons does chlorine (Cl) have?

How many electrons would two chlorine atoms have to share to become stable?

NONPOLAR Covalent Bond- EQUAL SHARING of electrons between

NONMETALS

Chlorine molecule

Chlorine atom

Chlorine atom

Valence Electrons

• How many valence electrons does hydrogen (H) have?

• How many valence electrons does chlorine (Cl) have?

• How many electrons would the atoms have to share to both be stable?

POLAR Covalent Bonds- UNEQUAL SHARING of electrons between

NONMETALS

+ -Partially positive charged end

Partially negative charged end

The shared electron will spend more time near the chlorine atom.

POLAR Covalent Bonds- UNEQUAL SHARING of electrons between

NONMETALS

+

-A water molecule is POLAR because it has a partially positive end and a partially negative end.