Chapter 8: Covalent Bonding Simulations and animations: Ionic and covalent bonding animation: http://www.youtube.com/watch?v=Qqj cCvzWwww Animation and song: what kinds of bonds are these: http://www.youtube.com/watch?v=oN BzyM6TcK8 Mark Rosengarten video tutorials on polarity of molecules: http://www.youtube.com/watch?v=mt RgeBSe1o8&feature=related glencoe animations and interactive lesson: http://glencoe.mcgraw- hill.com/sites/0078807239/student_vie w0/chapter9/concepts_in_motion.html # Animation: Ionic compounds versus nonpolar and polar molecules Properties of ionic and covalent compounds: Chapter 8: Covalent Bonding Resources: Chapter 8 of our TB and unit 6 of workbook Ch. 8 reading and study guide (in part) Powerpoint used in class Lab practical: Molecular models Handouts: practice problems and naming of covalent/molecular compounds Animations and simulation

Molecules and Molecular Compounds 8.1 Molecules and Molecular Compounds In nature, matter takes many forms. The noble gases, including helium and neon, are monatomic. That means they exist as single atoms. Represented by symbols: He, Ne, etc) the noble gases are not molecules The noble gases, including helium and neon, are monatomic. That means they exist as single atoms. Helium, being less dense than air, is often used to inflate balloons. The colors produced in what we commonly call neon lights are a result of passing an electric current through one or more noble gases.

Molecules and Molecular Compounds 8.1 Molecules and Molecular Compounds A molecule is a neutral group of atoms joined together by covalent bonds. Air contains oxygen molecules. A diatomic molecule is a molecule consisting of two atoms. An oxygen molecule is a diatomic molecule.

Molecules and Molecular Compounds 8.1 Molecules and Molecular Compounds Some elements do exist as diatomic molecules. Hydrogen H2 (g) Oxygen O2 (g) Fluorine F2 (g) Bromine Br2 (l) Iodine I2 (s) Nitrogen N2 (g) Chlorine Cl2 (g) The noble gases, including helium and neon, are monatomic. That means they exist as single atoms. Helium, being less dense than air, is often used to inflate balloons. The colors produced in what we commonly call neon lights are a result of passing an electric current through one or more noble gases.

Molecules and Molecular Compounds 8.1 Molecules and Molecular Compounds Pneumonic device to remember those elements that exist in nature as diatomic molecules.? (HOFBrINCl) (write out symbols, add 2 as a subscript) H O F Br I N Cl H2 O2 F2 Br2 I2 N2 Cl2 (note these are molecules but they are not compounds) The noble gases, including helium and neon, are monatomic. That means they exist as single atoms. Helium, being less dense than air, is often used to inflate balloons. The colors produced in what we commonly call neon lights are a result of passing an electric current through one or more noble gases.

Molecules and Molecular Compounds 8.1 Molecules and Molecular Compounds A compound composed of molecules is called a molecular compound. Water and carbon monoxide are molecular compounds. Water is a molecular compound with molecules composed of two hydrogen atoms and one oxygen atom. Carbon monoxide is a molecular compound with molecules composed of one carbon atom and one oxygen atom.

8.1 Formulas of Some Molecular Compounds Molecular Formulas The formula of a molecular compound indicates the numbers and kinds of atoms. The arrangement of the atoms within a molecule is called its molecular structure. Using Models Which of these molecules has the greatest number of oxygen atoms?

Molecules and Molecular Compounds 8.1 Molecules and Molecular Compounds Sodium chloride, which is an ionic compound, and water, which is a molecular compound, are compared here. Interpreting Diagrams How do molecular compounds differ from ionic compounds?

A molecular formula is the chemical formula of a molecular compound. 8.1 Molecular Formulas A molecular formula is the chemical formula of a molecular compound. A molecular formula shows how many atoms of each element a molecule contains.

8.1 Molecular Formulas Ammonia (NH3) is used in solution as a cleaning agent. You can represent the ammonia molecule by its molecular formula, its structural formula, a space-filling molecular model, a perspective drawing, or by a ball-and stick molecular model.

Molecules and Molecular Changes 8.1 Molecules and Molecular Changes Ethane, a component of natural gas, is also a molecular compound. Ethane is a component of natural gas. Inferring What information about the ethane molecule given by its molecular formula C2H6 is also given by the drawing shown here?

Chapter 8: Covalent Bonding Types of Bonding ? (review)

BONDING Sea of electrons model used to explain bonding in metals Metallic Bonding (ch 7) Sea of electrons model used to explain bonding in metals Kernel & delocalized mobile valence electrons BONDING

Metallic Bonding (ch 7) Ionic Bonding Electrostatic attraction of negatively and positively charged ions Can be formed as a result of the transfer of electrons between metal and nonmetal atoms to form cations and anions BONDING

BONDING Metallic Bonding (ch 7) Ionic Bonding (ch 7) Covalent Bonding (ch 8) Electrons are shared between atoms Covalent bonds may be nonpolar (equal sharing of electrons) or polar (unequal sharing of electrons ) BONDING

Types of Bonding Metallic Bonding (ch 7) Sea of electrons model used to explain bonding in metals Kernel & delocalized mobile valence electrons Ionic Bonding (ch 7) Electrostatic attraction of negatively and positively charged ions Can be formed as a result of the transfer of electrons between metal and nonmetal atoms to form cations and anions Covalent Bonding (ch 8) Electrons are shared between atoms Covalent bonds may be nonpolar (equal sharing of electrons) or polar (unequal sharing of electrons ) Types of Bonding

Bonding in: Na ? NaCl ? H2 or Cl2 ? HCl ? H2O ? Metallic Bonding (ch 7) Sea of electrons model used to explain bonding in metals Kernel & delocalized mobile valence electrons Ionic Bonding (ch 7) Electrostatic attraction of negatively and positively charged ions Can be formed as a result of the transfer of electrons between metal and nonmetal atoms to form cations and anions Covalent Bonding (ch 8) Electrons are shared between atoms Covalent bonds may be nonpolar covalent (equal sharing of electrons) or polar covalent (unequal sharing of electrons ) Bonding in: Na ? NaCl ? H2 or Cl2 ? HCl ? H2O ?

Molecules and Molecular Compounds 8.1 Molecules and Molecular Compounds Molecules and Molecular Compounds How are the melting points and boiling points of molecular compounds different from those of ionic compounds?

Molecules and Molecular Changes 8.1 Molecules and Molecular Changes Molecular compounds tend to have relatively lower melting and boiling points than ionic compounds.

Practice – properties of ionic and covalent compounds Go to interactive table on Glencoe site: Physical Properties of ionic and covalent compounds http://glencoe.mcgraw- hill.com/sites/0078807239/student_view0/chapter9/concepts_in_motion. html#

8.1 Section Quiz. 8.1.

8.1 Section Quiz. 1. Compared to ionic compounds, molecular compounds tend to have relatively low melting points and high boiling points. low melting points and low boiling points. high melting points and high boiling points. high melting points and low boiling points.

8.1 Section Quiz 2. A molecular compound usually consists of two metal atoms and a nonmetal atom. two nonmetal atoms and a metal atom. two or more metal atoms. two or more nonmetal atoms.

8.1 Section Quiz 3. A molecular formula shows how many atoms of each element a molecule contains. a molecule's structure. which atoms are bonded together. how atoms are arranged in space.