Ionic and Ionic and Covalent Covalent

CompoundsCompounds

How do ionic and covalent compounds compare?

• Ionic compounds make formula units

• Covalent compounds make molecules

How do ionic and covalent compounds compare?

• The strong attractions among positive and negative ions in an ionic compound result in a strong, three-dimensional crystal structure that is hard, brittle, and must be heated to high temperatures to melt.

How do ionic and covalent compounds compare?

• Covalent molecules do not have strong attractions, so they form liquids, gases, or relatively flexible solids

• The attractive forces between molecules of a covalent compound are weak because the molecules themselves have no charge.

How do ionic and covalent compounds compare? (cont.)

• Ionic compounds are electrolytes, compounds that conduct electricity when melted or dissolved in water.

• Covalent compounds are poor conductors of electricity.

How do ionic and covalent compounds compare? (cont.)

• Interparticle forces, or the forces between particles that make up a substance, are the key to determining the state of matter of a substance.

• The difference in strength of the interparticle forces in covalent compounds compared to ionic compounds explains differences in their properties.

What is another name for a molecular bond?

A. molecule

B. ionic bond

C. covalent bond

D. covalent compound

What forms when a metallic element and a nonmetallic element are combined?

A. ionic bond

B. covalent bond

C. covalent compound

D. noble gas configuration

What forms when a nonmetallic element and a nonmetallic element are combined?

A. ionic bond

B. covalent bond

C. covalent compound

D. noble gas configuration

Ionic vs CovalentIonic vs Covalent

IonicIonic CovalentCovalent

Melting PointMelting Point HighHigh LowLow

ConductivityConductivity High High (electrolytes)(electrolytes)

PoorPoor

Solubility in Solubility in waterwater

GoodGood Generally Generally poorpoor

Physical statePhysical state Brittle Brittle crystalscrystals

Liquids, Liquids, gases, or gases, or

flexible solidsflexible solids

Diatomic!Diatomic!

Di means ___________Di means ___________ Diatomic means ___________ Diatomic means ___________ These are elements that naturally These are elements that naturally

form molecules with themselvesform molecules with themselves They are found in molecules of They are found in molecules of

______________________________

2

2 atoms

2 of the same atom

Diatomics!Diatomics!

There are ________of them:There are ________of them: HH22

NN22

OO22

FF22

ClCl22

BrBr22

II22

seven

Diatomics!Diatomics!

Which of these is found as a diatomic molecule?

A. N

B. P

C. He

D. Se

What type of bond would complete the Lewis structure below?: N N :

A. an ionic bond

B. a single covalent bond

C. a double covalent bond

D. a triple covalent bond

Which type of compound dissolves more readily in water?

A. an ionic compound

B. a covalent compound

Which type of compound forms liquids, gases, or flexible solids?

A. an ionic compound

B. a covalent compound