CHEMICAL BONDING

• IONIC BONDS

• COVALENT BONDS

• METALLIC BONDS

IONIC BONDING

When an atom of a nonmetaltakes one or more valence

electronsfrom an atom of a metal

so both atoms end up witheight valence electrons

IONIC BONDING

IS THE COMPOUND AN IONIC COMPOUND?

METALMETAL NONMETAL

SUBSCRIPTS

IONIC BOND FORMATION

Neutral atoms come near each other. Electron(s) are transferred from the Metal atom to the Non-metal atom. They stick together because of electrostatic forces, like magnets.

IONIC BONDING

Metals will tend to lose electrons and become

POSITIVE CATIONS

Normal sodium atom loses one electron to become sodium ion

IONIC BONDING

Nonmetals will tend to gain electrons and become

NEGATIVE ANIONS

Normal chlorine atom gains an electron to become a chloride ion

Properties of Ionic Compounds

• Crystalline structure.

• A regular repeating arrangement of ions in the solid.

• Ions are strongly bonded.

• Structure is brittle.

• High melting points- because of strong forces between ions.

Do they Conduct?

• Conducting electricity is allowing charges to move.

• In a solid, the ions are locked in place.• Ionic solids are insulators.• When melted, the ions can move

around.• Melted ionic compounds conduct.• First get them to 800ºC.• Dissolved in water they conduct.

Examples

• Salts• Fertilizers• Baking soda

COVALENT BONDING

When an atom of one nonmetal

shares one or more electrons

with an atom of another

nonmetal so both atoms

end up witheight valence electrons

COVALENT BONDING

When a covalent bond is made it forms a

molecule. A molecule is a group of atoms held together by a chemical

bond.

COVALENT BONDING

COVALENT BONDING

IS THE COMPOUND A COVALENT COMPOUND?

NONMETALNONMETAL NONMETAL

YES since it is made of only nonmetal elementsYES since it is made of only nonmetal elements

Covalent bonding

• Fluorine has seven valence electrons

F

Covalent bonding

• Fluorine has seven valence electrons

• A second atom also has seven

F F

Covalent bonding Fluorine has seven valence electrons A second atom also has seven By sharing electrons

F F

Covalent bonding Fluorine has seven valence electrons A second atom also has seven By sharing electrons

F F

Covalent bonding Fluorine has seven valence electrons A second atom also has seven By sharing electrons

F F

Covalent bonding Fluorine has seven valence electrons A second atom also has seven By sharing electrons

F F

Covalent bonding Fluorine has seven valence electrons A second atom also has seven By sharing electrons

F F

Covalent bonding Fluorine has seven valence electrons A second atom also has seven By sharing electrons Both end with full orbitals

F F

Covalent bonding Fluorine has seven valence electrons A second atom also has seven By sharing electrons Both end with full orbitals

F F8 Valence electrons

Covalent bonding Fluorine has seven valence electrons A second atom also has seven By sharing electrons Both end with full orbitals

F F8 Valence electrons

COVALENT BONDING•Some molecules dissolve in water and some do not.

•Low melting points and boiling points- molecules are easily separated •Poor conductors

Examples•Water•Carbon dioxide•Gasoline•DNA•Plastic•Sugar•Diamond

Covalent Bonds

• https://smartsite.ucdavis.edu/access/content/user/00002950/bis10v/media/ch02/bond_types.html

Metallic Bonds

• Forms between metal atoms

• Metals hold onto their valence electrons very weakly. WEAK BONDS

• Think of them as positive ions floating in a sea of electrons.

Sea of Electrons

+ + + ++ + + +

+ + + +

• Electrons are free to move through the solid.

• Metals conduct electricity.

Metals are Malleable

• Hammered into shape (bend).

• Ductile - drawn into wires.