Chapter 8: Covalent Bonding

Section 1: Molecular Compounds

Molecules and Molecular Compounds

• Only ______ _______ exist as atoms• Ionic compounds

– Electrons are ____________– Electrostatic forces (+/-)– Similar ______________

• Molecular compounds – Electrons are _____________– Covalent bond- atoms share same electrons– Properties ________ greatly

• Ex. H2O, HCl, CO2

Molecules and Molecular Compounds

• Molecule– Group of atoms joined by ________ _______– Charge is _________

• Diatomic Molecule– Molecule of _______ _______

– Ex: O2, Cl2, CO

Molecules and Molecular Compounds

• Molecular Compounds– Compound composed of _____________– Molecules of one compound are _________

• Ex: all molecules of carbon monoxide (CO) are exactly the same

– Form from 2 or more ______________– Relatively ______ melting and boiling points– ________or _________ at room temperature

Ionic Compound vs. Molecular Compound

MoleculeFormula Unit

Practice

Ionic Compound or Molecular Compound?

1. MgBr2

2. C6H12O6

3. High melting temperature

4. Gas at room temperature

5. Conducts electricity

Molecular Formulas

• _________ and _________ of atoms present in a molecule of a compound– Not necessarily the ________ ______

_______ ratio– Actual number of _________ in the molecule

• Examples:H2O

Number of hydrogen atoms

No number shown, assume it means 1

CO

1 carbon atom

1 oxygen atom

PracticeHow many of each type of atom present in the

the following molecular compounds?

NH3

CO2

H2O2

C6H12O6

CHO

Molecular Formulas

• Do not tell the ________ of a molecule, only the _______ and ______ of atoms.– Text pg. 215

– Ex: H2O

Br2, CH4, SO3, N2H2, Ne2, KBr

• Do any of the above not exist?

• Which of the above represent molecules?

• Which of the above represent compounds?

• Identify each as an Ionic Compound or Molecular Compound.